It could be, what happens when you compile? Use the included compiler in 2020R2 as it saves all the faffing with Microsoft.https://forum.ansys.com/discussion/comment/101689#Comment_101689

Hi Rob, I had some problems with 'nmake' or something like that and later the library didn´t create. But I searched this errors and read some posts in this forum and after rewrite the code and solve these errors I could compile the code and the two pistons move correctly. Now I have to try to make the sealed system as you told.nThank you very much for your attention and your help.nIf I have any problem with the sealed system I will ask around here I guess.nAlso, I would like to read and learn something about the dynamic mesh methods, how they work and how should I use them, do you know where can I search for it?nSee you. n