You need to add a Dictionary for spell check to work. You can find one on the Extensions page by searching from there. It will then be added to a new Menu called Dictionaries.

Note you do not need a language pack or a combined extension with a pack.

https://www.google.ca/search?q=firefox+extensions+dictionaries&ie=utf-8&oe=utf-8&gws_rd=cr&dcr=0&ei=TQYKWrrsGIeU0gLelpa4Aw

Please let us know if this solved your issue or if need further assistance.

Went to extensions searched and found Oxford English dictionary. Added the dictionary but no new menu called Dictionaries has appeared.

samonty said

Went to extensions searched and found Oxford English dictionary. Added the dictionary but no new menu called Dictionaries has appeared.

Did you restart Firefox ?

Yes restarted Firefox

samonty said

Yes restarted Firefox

So copy/paste about:addons into the address Bar and then Enter There is no Dictionaries listed on the left side. ??

If not weird and wonder where it went. Is it listed in Extensions instead ?

Also I see that this one works by highlighting words and that there is a free and a paid version.

I have Canadian one installed and I have no issue.

Something is broken in 56.0.2

How about this Please uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. Then Install Full Version Final Release of Firefox 57 Quantum https://fileforum.betanews.com/detail/Mozilla-Firefox-for-Windows/1032985422/1 this is my daily fix site and gets releases a day early. It will be on Mozilla Servers tomorrow as a Full/update. Why wait. Note : Legacy Extensions will be disabled and or removed.

Please let us know if this solved your issue or if need further assistance.

Thanks for that I'll give it a go and let you know. By the way the dictionary is in Extensions.

That seems to have solved the problem, thank you for your patience and your help, much appreciated

Rgds

Sam