Hi Peter,
it look's that this is a website, which was updated from Joomla! 2.5 to 3.x?
On the Joomla! 2.5 version of the website you had installed Visforms in a Version lower than 2.0.0 which was neither uninstalled (or uninstalled incomplete) nor updated to the latest Visforms Version for Joomla! 2.5 before the Joomla! installation was updated to 3.x.
Actually it is really not possible to update from a Visforms version lower than 2.0.0 to a current Version.
There is an article in our documentation about migrating Visforms with a Joomla! update from 2.5 to 3.x
www.vi-solutions.de/en/documentations/vi...omla-2-5-to-joomla-3
and although it is not the most current article, what it says is basically correct.
I think the only way for you to get around this problem is to completely remove any remnants of the old Visforms installation from your Website and your database, especially the items in the #__extensions table. You can use the download of the latest Visforms Version for Joomla! 2.5 to find out, which files and folders you need to remove. And you have to check your database for "Visforms" and "Visfields" tables as well as for items in other tables which relate to Visforms.
Regards,
Aicha