Exception::getClass() in /home/phsto316/public_html/vqmod/vqcache/vq2-system_engine_front.php:61

New to opencart so no experience of what does what but do have a lot of experience of php
Running oc 2.2.0.0 on a site I'm transferring to a new host for somebody else

Site is operational but throws up some error messages
Error log has numerous entries
[03-Nov-2018 19:26:11 UTC] PHP Fatal error: Uncaught Error: Call to undefined method Exception::getClass() in /home/phsto316/public_html/vqmod/vqcache/vq2-system_engine_front.php:61
Stack trace:
#0 /home/phsto316/public_html/vqmod/vqcache/vq2-system_engine_front.php(52): Front->execute(Object(Exception))
#1 /home/phsto316/public_html/system/framework.php(99): Front->dispatch(Object(Exception), Object(Action))
#2 /home/phsto316/public_html/index.php(28): require_once('/home/phsto316/...')
#3 {main}
thrown in /home/phsto316/public_html/vqmod/vqcache/vq2-system_engine_front.php on line 61

Have tracked through line 61 and the getClass function is loaded when action.php is called. These files are present on the server and I think are being called correctly. Error is not present in log files of previous installation.

I see there is a previous forum entry on the same topic http://forum.opencart.com/viewtopic.php ... 2&p=617725 but the solution is "Your need remove files in folder vqmod/vqcache and all all vqmod extension files in folder vqmod/xml." . I find it hard to understand how deleting all these files will solve the problem and the entry doesn't seem to confirm that this is the correct solution. Also I have a separate copy of vqmod/vqcache within vqmod, is this necessary?

Thanks

Paul

Caused by an installed extension. Contact the extension developer to resolved this issue.