WP update causing site issues

Hi
I have been using my site now for just over a year without issues until this lastest WP update and since then my site has done nothing but play up.

Even after a restore backup process the problem is still there, I contacted my hosting provider for help but they also can’t find where the issue is.

The PROBLEM!
If you have a look at my domain name which I added here it has (/?v=6cc98ba2045f) after it and this has appeared after upgrading to the lastest version and I can’t find it anywhere to remove it as it is permanently displayed after every page on the website.
I also checked the config file, settings, and everywhere I can think of.

Help on where I can find this to permanently remove it would be greatly appreciated

Cheers.

The page I need help with: [log in to see the link]