Editor gets "Access denied" error using File Mgr to upload/create link

Website was recently updated to Revo v2.2.6pl, since which Editor user gets "Error: Access Denied" message when she clicks on the icon for the file manager and can't upload imgs/docs or create links to any already uploaded. No changes were made to permissions, afaik. Prior to upgrade she had no problem doing this.

I've checked the error log and only find a small number of these errors, not sure they're relevant:
"[2013-01-14 14:18:26] (ERROR @ /index.php) Could not retrieve data to cache for resource 106" (resource numbers vary; there are 7 of them to date, beginning date of upgrade).

I'd be grateful for any ideas. Editor needs to edit

Did you (when installed first) edit the default "Editor" Policy or did you duplicate it?

I also had this problem until I realized, that the default policies are always "reset" to what they are in a new installation when modx get updated. That's the reason an edited policy should always be a duplicate of a default one. So if you have changed the file_* permissions in the default Editor Policy, these settings will be gone after your update and the client cannot use the file browser anymore...

Thanks for your reply! You're right that the default policy itself might have been edited. I didn't personally set it up, so don't know for sure, but this user did have access to File Browser (to upload docs/imgs, and create links to them) and doesn't now, which is a real roadblock. I have avoided digging into the (overwhelming) permissions business and am therefore pretty clueless. Trial and error, here I come... What would be the name of that Access Policy? Not file_mgr, tried that and no access within to docs/imgs.