Class 'VmModel' not found error after upgrading to version 3.6.10

[deisa]

Hello,

After upgrading Virtuemart & VirtueMart AIO  from  v3.4.2 to v3.6.10 appears this error:   PHP Fatal error:  Class 'vObject' not found 
This error causes many HTTP ERROR 500.  How can I fix this error? It is urgent.

Thanks in advance.

error.log attached
Joomla! 3.9.14   PHP 7.2.1 

[balai]

Hi
Are you using any 3rd party extension like Custom Filters?
If yes please update to the latest version

[PRO]

what page and where?

have you tried disabling modules? plugins?

[deisa]

Hello,

This error occurs when make a preview mail or Spam Score and Preview with the extension RSMail! 1.22.17 from RSJoomla!

display this error:

This page does not work
The page www,xxxxxx.com cannot process this request now.
HTTP ERROR 500


Regards.

[deisa]

Hello,

Problem solved after deactivating the plugin  "Virtuemart plugin for Joomla! 3.x" .
I will inform to Rsjoomla of this problem...

Thank you so much for your help!