ServiceNow backend pages dont load following Zurich 10.3 upgrade

[jamesganley]

Hi 

I have recently upgraded a test instance from Zurich 4 to Zurich 10.3, following the upgrade my custom application pages load no problems. But when i go in to the backend to administer the instance non of the pages load? 
I can navigate to pages if i type the address in the URL but only pages that dont include /now so /now/nav/ui/classic just sits there doing nothing, but if i type /syslogs_list.do it loads. we have tried disabling polaris, rebuilding the polaris plugin but still nothing loads? 

at a bit of a loss as to the problem. 

thanks in advance 

[Dr Atul G- LNG]

Hi @jamesganley 

Sad to hear that. If this is a customer instance, I would recommend raising a ServiceNow Support case, as it looks like there may be an underlying issue.

If this is PDI, we can try resetting the instance if possible and see whether that resolves the issue.