General tasks are like the following while the problem is frequently occurring:
- Search files in Everything program
- Open (a searched folder) to Total Commander's TAB
- Use Multi-Rename Tool to rename multiple folders
- QuickSearch Extended plugins are being used
When I try renaming a folder, it is impossible to do so until TCMD is restarted. Once TCMD is relaunched, folder renaming is working again for some time. Then suddenly the problem occurs again. -> should quit TCMD

I'm using Totalcmd64.exe 8.51a in win 8.1 x64. What can be a problem?
ps. TCMD seems not close a file handle for some reason but I can't figure out. Obviously, I confirmed it in Process Explorer.