Content server error in 7.5.1 & 7.6

Hi. I was also receiving the server error from 7.5.1, but once I upgraded to 7.6 the server is now stuck on the loading page. I can no longer access the main library unless I click on the link for the non-Javascript version of the site.

My pc is using Win10. My device is using Android 5.1(Lollipop) and both browsers I have installed (Chrome & Kiwi) are compatible with Lollipop.

I know this may be an issue where my device's OS is now outdated. If I have to downgrade Calibre, what can I do to preserve my configuration/settings?

Thanks.