I have been working with the Addon for years now, saving a TiddlyWiki 5 with notes and one mGSD for my tasks. The mGSD is based on TiddlyWiki classic.
After the update to Friefox 68 the saving of TW5 works fine, but my mGSD (TW classic based) doesen't work any longer. Is there any help?

Update: Thank you for your hint and for working on the Addon!! The 0.3.10beta works wonderfully with FF 68 and 69.

Works really well, even when used in combination with other TiddlyWiki tools like TiddlyDesktop.

Great add-on for Firefox Quantum!
It saved my tiddlywiki classic pages.

Today my Firefox v52esr expired and was replaced by v60. That was the end of TiddlyFox.
I do have several old TiddlyWikis that are extremely important to me (a.o. 2 personal websites and my ToDo-system (GTD)). This extension was my saviour since it replaced TiddlyFox almost 1-to-1.
Many, many thanks to Mario Pietsch.

Vielen Dank für dieses Add-on zur Datensicherung von Tiddlywikis! Läuft seit Monaten wie eine Eins!

Great!

Thank you, thank you, thank you!!! You saved my #1 Knowledge Management System from becoming another fine piece of software that finally dies because of system improvements. I save my TiddlyWiki's on Dropbox so I can access them on any of my computers, where ever I happen to be. Since you can relocate your Dropbox folder (in Windows at least) using their desktop program, I relocated it within the Downloads folder and tested it out on Firefox 57.0.4. It works flawlessly! You are fantastic.
Jan 27, 2018, now that Firefox has updated to 58.0 it's not working :(
Jan 28, 2018 after researching around I found the fork of Firefox called Waterfox. Installed it and I'm again able to save my precious TiddlyWiki file :)

Due to my firefox's default download folder linking to a RAM disk, I created a symlink from tiddlywiki folder to ram disk sub-folder during windows start-up, and It won't affect the other ordinary downloads.