FF 57 .. 59 functionality missing

[wolfeph]

Running Firefox with Linux Mint.
I was happily working with FF, versiion up to 56. Starting with FF57 there is a lot of functions missing:
First of all: the most intensively used extension "Tab Mix Plus" (TMP) is no more available.

I upgraded to FF59 hoping functionality would become more smoothly: No!
First of all, middle click does no longer open a new tab by clicking a link. Sometinḿes a new tab opens by left clicking but not consistntly. It is just annoying. I tried to adjust this by use of the settings but there is not such an option. Anyway, the number of options to configure has become absolutely poor since FF57. Maybe it is because I am so much used to TMP.

On a page of TMP I read that allowing old-style extensions can be possible. Is that true?

O.K., I accept the latest development of FF, but is there any complete instruction for how to customize it?

[DanRaisch]

Legacy extensions like TMP were deprecated starting with Firefox 57 for security reasons. Unless the necessary elements are added to the base code, such extensions will not work with current versions of the browser.
See this thread for information on tweaking Firefox -- http://forums.mozillazine.org/viewtopic ... &t=3037817

[smsmith]

middle click does no longer open a new tab by clicking a link.

Type about:config in your address bar and hit enter. Press the I accept the risk! button. At the top of the page is a search field for the preferences. Type in browser.tabs.opentabfor.middleclick

If that preference is FALSE, double click it to change it to TRUE.