The Rebuild Site and Upload Image popup windows are not working in Firefox 0.93 with MT 3.1. The little popup window only reloads the current page inside of it instead of displaying the correct popup dialog. The Firefox JavaScript console is showing "Error: can't convert Error to string" each time these links are clicked.

I have edited the /tmpl/cms/header.tmpl file by hand so that the onclick attribute for these links is: "window.open(...); return false;" so that I can actually use them. However, the JavaScript console is still showing the error...I don't know the code well enough to know where it's actually coming from.

Possibly you may have to set your firefox to allow pop-ups from your own site in the settings of it. With me it does just fine as I did that.
Firefox has a pop-upblocker build in you know

I think you misunderstand the problem I ran into. I am not having trouble getting the popup to display. What I am having trouble with is getting the popup to display what it is supposed to.

I have had to go in and edit some of the JavaScript in the MT templates by hand so that, for example, the Rebuild Site popup actually has the buttons and things to rebuild the site. Otherwise, it just reloads the current page within the popup.

Did you upload the mt.js file in ASCII mode to the location you've designated for StaticWebPath?

I'm having similar problems with the rebuild button...either returns a "TypeError: e has no properties" or jumps to a completely foreign admin page or crashes FireFox.

That, and a myriad of weird problems with 3.12 upgrade from 2.64 that has me wondering why I bothered upgrading...never had MT probs before. Still plowing through a dozen reasonably serious problems that should not have been there, and now I can't work MT through my browser of choice.

Bad karma?

That problem is related to the buggy Tabbrowser Extensions being installed on Firefox installs

This thread will show you how to rebuild TBE but using plugins that are not buggy!

Thanks, arvind...that fixed that! Now on to the other dozen or so bugs...

Yes, I had uploaded the mt.js file properly. The javascript that I'd modified to work around the issue was in /tmpl/cms/header.tmpl. The root of the problem, however, turned out to be Tabbrowser Extensions, as arvind_2100 suggested. I uninstalled it and now my popup windows actually have things in them (after removing my modifications from the MT .tmpl file)...thanks arvind!