I notice this error in the event log quite often.
The process cannot access the file 'C:\Inetpub\vhosts\mydomain\httpdocs\Portals\1\Cache\Pages\1136_ACABA51644A302FBB325E30E7931BAF8.data.resources' because it is being used by another process.
It's not always the same file. Seems to potentially happen to all modules/pages.
I think I get the basics of this error - a cached resource is locked by the file system. But what might cause this? And how to fix it?