I have the same problem as @Evangelos. When I had AutoCad 2017 versions the lisp worked great. After updating AutoCad to 2023 the lisp does not work properly. It is only possible to replace single letters and characters for example: 2 can replace to 55, J can replace to Jacob. It is not possible to replace a longer string of characters than 1. Has anyone managed to solve this problem ? Maybe AutoDesk uses additional security to use paid versions.