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I've tried everything you suggested but it still does not let me compose any e mails . I am going to try and reinstall the yahoo this is the last thing I know to try. I will let you know if it worked.

I have same problem, but the biggest issue beyond crashing is that it won't autofill the contacts, and I figured out that adblock plus is the culprit, but i dont want to turn it off for security reasons, and i have searched ad block website to find out a script/code to put in filters to stop problem, if someone can tell me how to get around that and also the continous crashing in firefox while trying to us yahoo mail, this is beyond frustrating.

Load the web page. After the page is loaded, click the down arrow next to the AdBlock icon. Now select Disable on <web site>.

That does work in that it enables me to do auto fill, I am glad for that, however, it now is allowing those yahoo mail ads that are at the top of mail column, can I somehow disable that with a filter? but then again, I have disabled it for that webpage so I don't think I can kill off the ad if its all disabled. Or can I?

You can check here,

Forum; Adblock Plus Forum {web link} https://adblockplus.org/ Homepage

I did check there and got some direction, what I finally figured out to do is convoluted, and that is; I installed Yahoo Mail Hide Ad Panel which 1) kills off those ads so I can then 2) turn off Ad Block Plus on the page to compose my mail and thus use my autofill for contacts, while not being forced to see the ads which are hid by the Yahoo Mail Hide Ad Panel.

So, it does solve the problem in a roundabout way, I still hope and believe there is going to be a way to use script to set up the ad block to work but not stop the auto fill feature for yahoo mail. Interestingly, several articles are pointing out that very recently yahoo users are suffering the inability to access mail without TURNING OFF ADBLOCK... so that says a lot. Mind you, they are claiming only some users... testing...etc... yeah right, cynical but for sure I believe they did it to force their ads on those of us who use yahoo mail. too bad.

I appreciate all your answers to my problem but none of them helped I had already tried everything you suggested and even after running mozilla refresh that takes you back to the original state without any add-on including my ad block and yahoo mail ad block and I still had the same problem. I ended up re installing yahoo to take care of the problem even though yahoo said it wasn't their problem. It took care of mine. I had reinstall firefox and that didn't help either it was a problem specific to firefox and yahoo together because I could still compose mail and have it work properly with internet explorer or microsoft edge but not with firefox . Very strange , I don't know what the exact cause was just know the reinstall fixed it it was all such a pain having to re do everything again but I can't argue with the results.

As long as it works. Please flagged Today at 3:09 PM as Solved Problem This may help others.