permission check hangs while it worked before

Hey

Finally a plugin that clearly checks the wrong permissions on file and folders.

However, it worked nicely and then it stopped working, just waiting forever. On other sites, it still works nicely.
I had my site moved to a newer server. The wordpress seems to have sufficient permissions to go through all the files. Anyone an idea what could be have gone wrong?

Already uninstalled and reinstalled, nada.