A similiar problem was already discussed at  Issue: The file/folder name is not valid, which is marked as resolved as of 665. However, it seems to be existing still.
- When trying to rename any folder (folder name not relevant, both in file and tree pane, also with F2 rename dialog), FC gives an error message: "element not found. retry/abort?". Nothing has happend up to this moment. Hitting "abort" aborts.
Screenshot: Error - Not Found
Funnily, this error message is in German (my Windows language, as opposed to using FCXE in English). So this seems to be originating from the underlying OS, not from FCXE itself, maybe?English text of German error message:
Element was not found.
The element is no longer at C:\download\test-fc. Check the location of the element and try again.
- Hitting "retry" yields yet another error message: "Operation failed." At this time, the folder has been renamed, yet FreeCommander has not registered it (also not updated file view).
Screenshot: Error - Failed
- Acknowledging this error returns to the previous error message "element not found". From now on, the error dialogs keep returning. Canceling returns to FreeCommander with the not-updated file view. Refreshing the view shows that the folder has been renamed.
Screenshot: Renamed folder
- FC not finding (?) the file before the rename action
- FC not recognizing the rename having been performed (possibly resulting from circumstances also leading to the first error?)