Many site issues can be caused by corrupt cookies or cache.

• Clear the Cache and

• Remove Cookies
  Warning ! ! This will log you out of sites you're logged in to.

Type about:preferences<Enter> in the address bar.

• Cookies; Select Privacy. Under History, select Firefox will Use Custom Settings. Press the button on the right side called Show Cookies. Use the search bar to look for the site. Note; There may be more than one entry. Remove All of them.
• Cache; Select Advanced > Network. Across from Cached Web Content, Press Clear Now.

If there is still a problem, Start Firefox in Safe Mode {web link} While you are in safe mode;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Then restart.

Still a no go.

It's definitely the update to V45 that's causing it. On my alternate computer I tried loading Google Inbox prior to updating Firefox and it loaded fine. I then updated Firefox to V45 and now Inbox won't load.

You did try Firefox Safe Mode, Yes? I've called the big guys to help you. Good luck.

Install an older version of Firefox {web link}

Firefox safe mode was one of the first things I tried. I didn't notice anything else that was broken after updating, but it definitely started with Google Inbox after applying the update to V45.

A bug report has ben filed: https://bugzilla.mozilla.org/show_bug.cgi?id=1255082

Just found out on Inbox forums that setting Inbox to accept third party cookies in Firefox solves the problem. I tried adding Inbox as an exception and now Inbox loads properly.

The bug has been fixed in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1257861

Probably in the next routine update.