Cannot edit "contententry" template in v5.1.0

[SiFor]

After upgrading to v5.1.0 I wish to make some changes to the contententry temaplte in version that were in the previous version but cannot, the below message is displayed. Even if I open the temaplte make no changes and try to save I get the same error! I even tried with a brand new temaplte and I get the same error by just opening "contententry" and trying to save!

The following error occurred when attempting to evaluate this template:

Warning: Illegal string offset 'vbforum_text' in [path]/includes/adminfunctions_template.php(4764) : eval()'d code on line 23

Warning: Illegal string offset 'vbforum_gallery' in [path]/includes/adminfunctions_template.php(4764) : eval()'d code on line 30

Warning: Illegal string offset 'vbforum_poll' in [path]/includes/adminfunctions_template.php(4764) : eval()'d code on line 37

Warning: Illegal string offset 'vbforum_video' in [path]/includes/adminfunctions_template.php(4764) : eval()'d code on line 44

Warning: Illegal string offset 'vbforum_link' in [path]/includes/adminfunctions_template.php(4764) : eval()'d code on line 51

This is likely caused by a malformed conditional statement. It is highly recommended that you fix this error before continuing, but you may continue as-is if you wish.

[SiFor]

A little more info

I upgraded my test forum and tested and I dont get this issue. So its only on the customer site.

I also disabled all plugins via config.php on the effected site and I still have the issue?

[Zachery]

I'd re-upload the files and re-run the upgrader again to have it reimport and rebuild the master style