Rack file corrupted during session

I am working on polar workflow with multiple loop on multiple step of mesh adaptation. Each step of adaptation call pegaase capsule. I have a python file written by my pegaase capsule, it is the same file for all of the pegaase call in my session. So that the file always have the same checksum. Randomly my file became completely empty at one iteration. Even if the file I try to store is not empty.