Iv'e searched some of the net trying to see if I can locate that error,but can only find this part of the error that you reference to when you try to recover the drawing:
Press ENTER to continue:
Error 53 (eFilerError) Object discarded
Reading handle ?? object type ??
Error 53 (eFilerError) Object discarded
In the few cases I've found it says the drawing is corrupt.Heres a hold load of help I found a forum ages ago about drawing recovery/file corruption.There doesnt seem to a great deal of help out there on your problem so maybe this'll guide you in the right direction.
Drawing files can become corrupt for many reasons. The most common cause for corruption is when a drawing file is copied onto a floppy drive or a hard drive that contains damaged sectors. In this situation, some or all of the file(s) copied onto the damaged sectors become unreadable. Other sources of file corruption include defective computer RAM, power surges, usage errors, and network file transmission problems. Another cause for file corruption, although infrequent, is when AutoCAD shuts down unexpectedly while the drawing is opened. Also, drawings originating from other software packages that have been translated into DXF™ or DWG format can also suffer through the file translation. The most effective way to guard against this type of data loss is to make frequent backup files of your drawings. Although this document explains different ways of recovering corrupt drawings, file recovery is not always completely successful. Even when a drawing can be recovered, some part of the file is often corrupt beyond recovery, therefore you must identify the part(s) of the file that were not recovered and consequently recreate the data. Instead, it is obviously better to use a "good" backup of a drawing so that you know exactly what data is contained in the drawing based on when the last backup was made.
Solution:
Note that most of the recovery methods explained in this document can be used in all releases of AutoCAD® and AutoCAD LT® software.
Before Recovering a Drawing
It is strongly recommended you perform the following steps before recovering
Make a copy or copies of drawing onto reliable storage media. For example, if you suspect that your hard drive contains bad sectors, copy your files to either another hard drive, a network drive, a floppy disk or to tape. It is best to perform recovery operations on a copy of the file, since there are several different methods of recovery, and each method alters the file in a differentway. For each recovery method, it is best to use a copy of the original file since recovery processes may alter a damaged drawing yet still not recover it enough that AutoCAD can open it. If you retain a copy of the original damaged file, you can then use another recovery process on the original file.
Identify and make back up copies of .BAK files associated with the damaged drawing. If you open and save a damaged file without fully recovering it, you may overwrite a good .BAK file with a corrupt .BAK file.
Note that there is a mechanism in AutoCAD that prevents a good .BAK file from being over-written by a corrupt .BAK file. When AutoCAD saves a drawing, it also checks the file for corruption. If the file is corrupt, AutoCAD does not overwrite the existing .BAK file. Instead it creates backup files that have the extension(s) .BK1, .BK2, .BK3, etc. Be aware this process is not always successful, therefore it is a good idea to make archive copies of good .BAK files if you suspect that you have a corrupt file.
Try to identify the source of the corruption. For example, if you suspect that drawings are becoming corrupt by copying files onto a hard disk with bad sectors, you should identify and correct the problem with the hard disk before you begin to recover your files. By doing some investigation, you may find that there is more than one source that is causing the corruption or that your original assumption about what is causing the problem is incorrect.
Record any error messages generated by AutoCAD or the operating system. Note when the messages occur in order to find a connection between the messages and when the drawing becomes corrupt. Continue to record any errors or messages that are generated during the recovery process.
AutoCAD RECOVER Command
To use the RECOVER command on a damaged drawing, launch AutoCAD and open a new drawing with no prototype. Use the OPEN command to open the drawing. If AutoCAD detects that it is corrupt, it displays a message indicating the file is damaged. AutoCAD then prompts you to use the RECOVER command to open the drawing and displays a message asking you to enter YES to proceed. If you proceed, AutoCAD then scans through the drawing database to detect and fix errors. If the RECOVER process repairs the file so that it can be opened, AutoCAD then opens the drawing and displays a message at the command line similar to the following message:
Command: RECOVER
Drawing recovery.
Drawing recovery log.
Scanning completed.
Validating objects in the handle table.
Valid objects 10033 Invalid objects 0
Validating objects completed.
Used contingency data.
Salvaged database from drawing.
0 Blocks audited
Pass 1 10000 objects audited
Pass 2 10000 objects audited
Pass 3 10000 objects audited
Total errors found 720 fixed 720
Regenerating drawing.
If the RECOVER feature cannot repair the drawing, AutoCAD displays one of several messages to indicate that the file cannot be recovered. If the drawing is severely corrupt, the recovery process may lock up or AutoCAD may shut down. If this happens, you need to reboot the computer and try a different recovery method. If the drawing can be opened with the RECOVER command, you should next use the AUDIT command. It is possible to have a drawing that contains "nested" damage that cannot be fixed by the RECOVER process on the first pass. In this situation, use the AUDIT process once or several times to fix this type of damage. To begin, enter the AUDIT command. You will be asked if you want the AUDIT process to attempt to fix any errors it encounters. Press the Y key to accept this choice and begin the AUDIT process. AutoCAD will now scan through the existing open drawing and attempt to find and fix errors. The AUDIT will display a report of the audit process at the command line similar to the report below: (press the F2 key when Audit is complete to view the entire report.)
Fix any errors detected? <N>
0 Blocks audited
Pass 1 10000 objects audited
Pass 2 10000 objects audited
Pass 3 10000 objects audited
Total errors found 16 fixed 16
If AUDIT finds and fixes errors, you should run the process again until it no longer finds errors. Be aware that AUDIT may find errors that it cannot fix. Also, the AUDIT process will sometimes report that it has found and fixed errors in the drawing, but subsequent AUDITs will report finding and fixing the same number of errors. If this occurs, try to either run the RECOVER process again or try one of the other recovery methods described in the rest of the document.
Using the INSERT Command to Recover Drawings:
It is sometimes possible to use the INSERT command to recover a damaged drawing. If the RECOVER command cannot successfully open a drawing, you may be able to insert the drawing into another drawing as if it were an external block. The following explains how to do this:
1. Start AutoCAD and open a new drawing. Be sure to not open a prototype drawing.
2. Enter DDINSERT at the command line command or select INSERT > BLOCK
from the DRAW menu to display the INSERT dialog box.
3. Press the FILE... button and select the damaged drawing from the Select Drawing File dialog box.
4. Remove the check from the "Specify Parameters Onscreen" checkbox, and place a check in the "Explode" checkbox.
5. Choose OK in the INSERT dialog box. AutoCAD attempts to insert and explode the damaged drawing. If the process succeeds, run the AUDIT command as described in the preceding section "AutoCAD RECOVER Command".
WBLOCK Command for Saving Parts of a Drawing:
If you have a drawing that can be opened but AUDIT cannot fix, use the WBLOCK command to extract entities from the damaged file. This method is also good to use on a drawings that become corrupt again even though the RECOVER feature was successful.
The following steps show how to use the WBLOCK command:
1. Start AutoCAD and open the drawing.
2. Set all of the layers in the drawing to ON, THAWED and UNLOCKED.
3. Enter WBLOCK at the command line to create a new external block. Provide a name for the block in the Create Drawing File dialog box.
4. Enter a name for the internal block (or press the Enter key). Then select an insertion point.
5. Select all the objects in the drawing by entering ALL at the command line or by manually selecting all the objects using a crossing window.
6. Close the current drawing after the external block is created without saving the changes and open the external block file.
7. Run AUDIT on this drawing to test the file for corruption.
If running AUDIT on this drawing reports it finds errors, discard this file and reopen the original damaged file. The following discusses two methods for how to proceed. The first method should be used on a drawing that contains less than 20 layers; the second method should be used on drawings that contain more than 30 layers.
Method #1 - For drawings containing less than 30 layers
Freeze all the layers in the drawing except for the first layer in the layer list and create an external Block from the data on this layer. Open the external Block file as described in the preceding section and perform an AUDIT. If AUDIT reports errors, discard this drawing, reopen the damaged file and create an external block that contains only the data on the second layer in the layer list. Repeat this process until you have determined which layers in the damaged file contain corrupt data. Use WBLOCK to create an external block that contains all the objects on layers that do not contain corrupt data.
Method #2 - For drawings containing more than 30 layers
Set all of the layers in the drawing file to ON, THAWED and UNLOCKED. Next, ZOOM to the drawing extents. Use the WBLOCK command to create an external block from all the objects in the upper right quarter of the screen area. Repeat this process for the other three quarters of the drawing. Next, open each quadrant drawing separately and run the AUDIT process on each. One or more of the quadrants will fail the AUDIT process. Divide these quadrants into quarters and repeat this process until you have identified all or many of the quadrants that do not report errors when AUDITed. These quadrants can then be reassembled into a single drawing.
Drawing Recovery using DXFOUT and DXFIN:
AutoCAD contains a translator for creating Drawing Exchange Format (DXF™) files from .DWG files. It is possible to use the DXF conversion process to fix damaged drawings. However, the DXF translator was not designed for recovering drawings, therefore this process will not work on drawings that contain a lot of damaged data. Also, the error and warning messages that appear during the DXF translation are not meant to provide detailed information about the status of drawing damage or
recovery. To use the DXF translator to recover a file, you need to open the drawing in AutoCAD and then immediately cancel the first automatic regeneration process that occurs when the drawing is opened. If you can perform this step, you can use the DXF translator to create a .DXF file. You can then either re-translate the .DXF file into a .DWG file or repair the .DXF file manually by editing it in an ASCII text editor, such as Microsoft® Notepad.
1. Start AutoCAD and select the OPEN command from the File pull-down menu, or enter OPEN at the command line.
2. Select the damaged drawing from the File dialog box to open it.
3. Choose OK in the Select File dialog to open the drawing and immediately press the Escape key to cancel the current command. (If you are using MS-DOS® AutoCAD or if you have configured Windows AutoCAD as "Classic AutoCAD", you must press the Ctrl+C keys).
This process should cancel the first regeneration of the drawing. If the drawing can be opened, the AutoCAD command prompt will appear. (You may want to practice this process with an undamaged file in order to obtain a sense of how to this.) Next, enter DXFOUT at the command line. You are then prompted to enter a name for the .DXF file and to specify the level of accuracy for the file translation. The
translation process begins when the level of accuracy is entered. Refer to the AutoCAD User?s Guide, Chapter 14, File Management and Formats, for more information about .DXF files and translation choices. After the DXF file is created, re-import the file into AutoCAD using the DXFIN command. To import the file into AutoCAD, open a new drawing (no prototype) and enter the DXFIN at the command line and select the DXF file you created. The file is then-translated again into an AutoCAD .DWG file. If the DXFIN process fails, you can view and edit the .DXF file in an ASCII text editor. A .DXF file is a complete translation of the drawing into ASCII text. Refer to the AutoCAD Customization Guide for a description of the contents and structure of a .DXF file. If you prefer not to learn the structure of DXF files, you can scan the file for obvious anomalies or corruption, or possibly truncate or remove sections of the file in order to salvage some data.
Sources of Drawing File Corruption:
As noted in the Introduction, file corruption can occur for a number of reasons. If you discover that you have a damaged drawing, it is important to track down and eliminate the source of corruption to prevent the problem from recurring. This section describes some of the most common reasons and recommends possible solutions.
Cause #1
A drawing can become corrupt because it is copied to a floppy drive or hard drive that contains defective sectors. Also, a drawing on a floppy drive or hard drive can become corrupt because the drive is damaged due to a power surge or other type of physical damage.
Solutions/Suggestions
Use the tools provided with the operating system, such as Scandisk (provided with Windows® and MS- DOS), to detect flaws in the physical media. Also, third-party diagnostic applications, such as Norton Utilities, can detect, and in some cases, prevent future access to damaged sectors on physical media. Suggested drawing recovery procedures include the steps listed above. Also, files
can sometimes be recovered from damaged physical media by computer hardware service providers.
Cause #2
A drawing can become corrupt because the System RAM is defective. When the drawing is edited in AutoCAD, the file is copied into and out of RAM and is not correctly written back to the hard disk.
Solutions/Suggestion:
This problem usually manifests itself in other areas, such as corrupt operating system files or failure to run AutoCAD and other programs, before you experience corrupt AutoCAD drawings. If you encounter any of the following problems, you should check the integrity of the system RAM:
?? Drawings become corrupt
?? System terminates unexpectedly
?? Error messages occur in AutoCAD and other programs
Several third-party diagnostic applications, such as Norton Utilities, can detect flaws in system RAM.
Cause #3
A drawing can sometimes become corrupt if an AutoCAD session is terminated while the drawing is open in AutoCAD.
Solutions/Suggestion:
Drawings are not easily made corrupt while opened in an AutoCAD. When a drawing is open and changes are made, the new or edited data is stored in temporary files. When a SAVE is performed, the information in the temporary files is written to the drawing database. If an AutoCAD session is terminated between SAVEs, the data in the temporary files is lost, therefore, the drawing will not contain any of the changes from the current editing session. However, if an AutoCAD session is shut down unexpectedly during a SAVE operation, it is sometimes possible to corrupt the open file. If AutoCAD shuts down unexpectedly, it is usually because of memory conflicts with other applications on a system, or a lack of system resources. If your installation of AutoCAD shuts down unexpectedly (even if drawings do not become corrupt), you should diagnose the problem by eliminating the possibility of a memory conflict or a shortage of system resources.
Cause #4
Drawings or .DXF files from other CAD applications will not open in AutoCAD because of file translation problems.
Solutions/Suggestion:
Files from other CAD applications will sometimes generate error messages when you open them in AutoCAD. In most cases, the application that created the file has not created the .DWG or .DXF file correctly. You should confirm the file is not actually corrupt by opening it in the original application and running the equivalent of the RECOVER command in that application.
In some cases a .DWG or a .DXF file created by another CAD package is meant to be used only with a specific release of AutoCAD. For example, a CAD application might only produce .DXF files that can be opened in AutoCAD Release 12 and not Release 13. The documentation for the application that produced the file will generally provide information about compatibility with the various releases of AutoCAD.
