I just started having this problem. If I search for a youtube video I can play it but every this else is greyed out. If I just got to youtube.com every this is grey and can not do any thing nothing works. Just grey screen with grey boxes. I have searched the internet and tried what was suggested. Cleared ,cookies. cache, history nothing works. If I use Firefox every thing is fine.
Ok I am getting a little tire of Seamonkey after all these years. I have created a couple of different profiles. One works with bank logins, gmail and other sites, but will not work with youtube. The other works with youtube and gmail but gets security errors with banks. The third one works with bank sites but youtube is greyed out and not with gmail. I have deleted seamonkey reinstalled and still have problems. I guess I will have to have different browsers for every thing I do.
I have created a couple of different profiles. One works with bank logins, gmail and other sites, but will not work with youtube. The other works with youtube and gmail but gets security errors with banks. The third one works with bank sites but youtube is greyed out and not with gmail.
Well, I don't think you need to create any more profiles. I suggest you go here with each profile - www.whatismybrowser.com/detect/what-is-my-user-agent and see what User Agent each is showing. Also check in about:config for any site specific user agents you may have set.
This is what it is what the user agent is saying "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0" I've done all the cookie and cache things. When I try to log onto this site using seamonkey I get a text page and any link I click I get a capta then click the images and then get another and another capta. So I have to use firefox.