The company has the following VPN setup...
Server is at main location with 192.168.254.x subnet.
Client is at a satellite location with 192.168.1.x subnet.
Devices can ping/access each other by name all day long.
Server has a shared data drive with the following permissions that are propagated to child objects...
(Domain) Administrators - Full Control
CREATOR OWNER - Full Control
Everyone - Full Control
SYSTEM - Full Control
(Domain) Users- Full Control
Above client receives "the folder is marked as read-only" error when trying to save to a shared folder on the server. If they save the excel file locally, then they can copy the file to the shared folder. Tested that they can create/modify/delete notepad files in the shared folder. Excel seems to be the only program affected.
I should also mention that the Excel file to be saved is generated by a third-party program installed on the client. Program saves the file to client's local drive, file is opened, modified, and can be saved to any location but the shared folder, without error.