Thread:Project:Support desk/Problem With File Upload: Could not acquire lock for "mwstore://local-backend/local-public/1/1e"./reply (25)

Well, the changes I suggested was a still undocumented way to specify a null lock manager, because the filesystem you're using to store images doesn't allow locking files to prevent race conditions, something that MediaWiki is using by default.

The error message it's obfuscating the real directory which it's trying to create, under mwstore://local-backend/local-public/.... You could try to set a debug log file to see if it gives the exact directory it's trying to create and see if it's really the directory you're expecting to use. Maybe there's another configuration typo making it point to another directory.