Page Versions stopped working after 5.4 to 5.5 upgrade?

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After upgrading a site from 5.4.1.1 to 5.5.2.1 page versions does not open properly?
I think it normally uses ajax or java to open but now when you click to open versions ether on the page or from the sitemap it loads in full page and does not allow you to approve delete or compare anything.

see attachment

can anyone help please?
thanks

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