How to find a location of a dll ( or a package)

Question

I use windows 11 (the same problem was in win 10 as well). I use oracle VM as well. The operation system in VM is windows 7.

I installed my delphi 6 IDE in a folder shared between windows 11 and windows 7 in VM.

My delphi main module uses my package (a kind of dll). I can compile my package without problem. But when I compile the main module, I always get an error, it says a new variable is not declared, but it is declared in the latest version of the package. So it seems the main module always look at an old version of my package in the memory.

I have searched the package in my windows 11 and windows 7, I couldn't find a old version of the package. Restarting PC does not fix the problem.

My questions are

1. how to unload the old version package from memory
2. how to write a program (delphi or c#) to find out the location of the old package?

Thanks.