The error being raised was:
Method 'PrepareEditOpen' not implemented for repository 'CSTest2'
There was no problem accessing the test documents from the Content Server 10.5.0 web UI or via WebDAV.
Since the issue was showing up on the clients, I decided to turn on error logging in Enterprise Connect
Enabling Enterprise Connect Logging
1.Right-clicking the Enterprise Connect desktop icon.
2. Choose "Options" from the pop-up contextual menu.
3. When the Options window appears, click the "Logging Options..." button.
4. On the Logging Options page, check "Log Enabled" and select "Error" from the "Apply to All" drop down menu.
5. Set the "File Location" field to which ever folder works best for you.
6. Click the "Apply" and "Exit" buttons. Close the Options window.
7. Logout of Windows and login in again to activate logging.
At this point, I reproduced the error trying to view a document in Content Server using the Enterprise Connect client. when the error was reproduced, go back into the logging options and disable logging.
On my test machine, three logs were created: uc_explorer.log, uc_ucscore.log and uc_ucsync.log. Open the uc_ucscore.log file in your favorite text editor. I suggest Notepad++ over Notepad.
Scroll down to the bottom of the log to see the errors. I found the following:
08:15:18.41 [UCSCORE ](4588): ERROR: Could not get service.
08:15:21.58 [UCSCORE ](4588): ERROR: Can't query Office Editor Documents: Could not find a part of the path 'C:\Users\[WindowsAccountName]\AppData\Roaming\OpenText\OTEdit\[CSInstanceName]\c2149\'.
During my investigation, I noticed that the \c2149\ folder was not created on my client. Don't get fooled by that error message. The real clue was the next line:
exception.message=Server not capable of Webedit.Unreserve;
This error says that the Content Server webedit module can't do it's job.
To verify the problem was with the Content Server instance and not the Enterprise Connect client installed on the PC, I added another URL connection string to Enterprise Connect for a disaster recovery instance and tested the ability to open documents. Enterprise Connect was able to open a copy of a test document that was in the DR instance just fine. So, the problem was at the QA Content Server.
Taking a look at the installed modules, I quickly discovered that the OpenText Enterprise Connect, Email Services and Content Server Web Edit modules where all at version 10.5.0. The Enterprise Connect client being tested as 10.5.2.
To finally resolve the issue, I backed up the OTHome directory (the path Content Server is installed into) and the SQL database and performed the upgrades to each of the modules to bring them up to version 10.5.2. Once that was complete, the QA test clients were able to open, edit and update documents without further trouble.