Hello everyone,nnI tried your advice and the error came up again.nI checked my previous project (which I made and evaluate in 2020R2 student version, and now I use 2021R student version) and in this project I create a new topology optimization study. If I run the optimization study whit the saved results, it works. If I clear the saved value and solve again and run the topology optimization than it is doesn't work and the error come up.nDoes anyone any idea why is this happening and how can I solve the problem?nRegards,nn