Thank for your reply, so sorry I didn't get back to your post earlier.
I did find a resolution after further investigations:
- Creating new Excel documents, once saved and re-opened experience the same read only issue, this is locally and from a network share location.
- If the Excel files are opened from within the Excel application, they open fine, can be edited, saved and re-opened as normal. This is the same for files stored locally and from a network share.
As the issue reported happens from within terminal server sessions I have completed the same checks from the users desktop PC and there are no issue's with Excel files opening as read only, everything worked as expected.
One thing I did notice, when opening the Excel application on the terminal server session we received an error message regarding a missing add in dll file (SGXLADDIN.dll).
In the end the resolution was to remove the orphaned SGXLADDIN.dll file from Excel Add-ins.
Kindest Regards
Phill