Cannot click on sub-menus and notification prompts in Mircosoft Exchange when using Firefox.

Question

When I access Microsoft Exchange web app from Firefox I've can no longer click on pop-up sub-menus and notifications that I could previous use.
For example, when I go to empty my deleted items folder and select empty folder, I get this notification (menu 1) that I now cannot click on. All I can do is just hit 'enter' to close the menus without actually making a yes/no input.
Similarly, when i go to move folders and get this pop-up menu (menu 2), I cannot make any selection, and the 'enter' to close method does not work. All I can do then is close the page.
I have tried disabling firefox's pop-up blocker but that did not rectify the issue. I can still use the sub-menus in other web browsers so this is a firefox specific problem.
Any help in identifying the cause and remedying this would be greatly appreciated.

Answer 1

Many site issues can be caused by corrupt cookies or cache.
* Clear the Cache and
* Remove Cookies<br> '''''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,
'''[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode 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.
If there is still a problem;
Start '''[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Firefox in Safe Mode]''' {web Link} by holding down the '''<Shift><br> ''(Mac Options)'' ''' key, and then starting Firefox. Is the problem still there?