I use Firefox and I usually have a number of tabs open and very often I open two Firefox’s to accommodate all the tabs I have opened. This usually is no problem, but lately FF will get really sluggish and slow to respond and this message always pops up when this happens. I’m not very tech savvy and don’t know what’s going on. Any help is greatly appreciated.
*A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue.
In plain English, you have too many tabs open. And using multiple incidences of FF is hurting, not helping.
There’s also some risk of causing problems on some sites that aren’t too smart by opening several tabs at once on the same site. Especially for sites where clickable links mostly change part of the current page rather than creating a complete fresh page. Trying to bypass their idea of how it’s supposed to work by having mutliple pages open at different points in the same dialog, for example, can trigger bugs in the scripts that are assuming they’re only being used on one page at a time.
Stop doing that and your problems will probably go away.
Another potential cause is you’ve got aggressive ad blocking and they’ve tried to design their site to fail unless / until you turn off the ad blocking.