Why does Adobe tool SignPlugIn frequently throw "can't update resource in plugin" error?

Why does Adobe tool SignPlugIn frequently throw "can't update resource in plugin" error? It occurs once every 3 tries and seems less often if runs on the machine with fast hard drive.

Procmon,i.e. process monitor, log shows that Adobe tool failed to access .api file because of a file named "RCXEBnn.tmp".