If it works in safe mode that means there is a addon issues. You have to turn off and on each one to find out which is the problem.

Just found this..... https://www.pcmag.com/news/googles-chrome-browser-starts-disabling-ublock-origin. Whatever next.

That headline has nothing to do with the Firefox web browser though.

Also the JavaScript built in Firefox and the Java Plugin are two separate things and have no relation. JavaScript was originally going to be called LiveScript which would have reduced the confusion between the two all these years. https://kb.mozillazine.org/JavaScript_is_not_Java

Firefox has not allowed NPAPI Plugins to run in Firefox since Firefox 53.0 (including Java) though the Flash Player Plugin supported was removed later on. https://support.mozilla.org/en-US/kb/npapi-plugins

So your issue may likely be due to one or Extensions you have installed in Firefox as a number of them can affect how JavaScript works in Firefox, especially the NoScript extension.

May I try and be clearer, When I Google search I get a no Java script error 'Google turn on Java to continue browsing' message.

I use Firefox plug-in 'OpenH264', it worked merrily away until a day or two ago, one day it didn't work afew hours later it did..... now it won't work at all.

I tried in Browser safe-mode as was suggested and it worked, it worked everytime. I tried to update Open264 and it won't update, hoping this helps to clarify.

Dave

Sorry for the 'longish' delay. Sorted..... I simply re-installed uBlock. I guess what threw me was thinking it was a Java issue, I did try turning Java off ann 'on' in uBlock but that made no difference. I was about to re-install Firefox and thoght re-installing uBlock be easier...... and it was! Kinda gob-smakced when it worked.

Thank you all for your help, much appreciated. problem solved and back to normal.

Dave