Automat » Does not work, help!

Script error in [Greasemonkey script github/BastianKanaan/GMscripts_MyFreeFarm/MyFreeFarm Automat; version 2.9.77]:
ReferenceError: GM_getValue is not defined MyFreeFarm Automat:16679:19
Script error in [Greasemonkey script github/BastianKanaan/GMscripts_MyFreeFarm/MyFreeFarm Berater; version 2.10.99]:
ReferenceError: GM_getValue is not defined MyFreeFarm Berater:26907:19
Script error in [Greasemonkey script github.com/linus--tux/GMscripts_MyFreeFarm/MyFreeFarm Common functions; version 2.1.12]:
ReferenceError: GM_getValue is not defined MyFreeFarm Common functions:1585:19
Script error in [Greasemonkey script github/BastianKanaan/GMscripts_MyFreeFarm/MyFreeFarm Rackoverview; version 2.0.2]:
ReferenceError: GM_getValue is not defined MyFreeFarm Rackoverview:2582:19

(Posted same in Berater, as it concerns both scripts)

Latest firefox, latest greasemonkey. Is it possible to install older versions of ff alongside current ones?
Edit: Using firefox 86
Edit2: Perhaps it should be listed somewhere, that the script requires firefox 56?
Edit3: Listing firefox 56 downloads for future people: https://ftp.mozilla.org/pub/firefox/releases/56.0/
Edit4: Installed FF 56 and the greasemonkey verison you recommended. Then installed the berater and automat scripts. But nothing on the myfreefarm page changed (i verified that the scripts are running). Also there's nothing in the console.

Fixed!
These are the steps:

1. Disconnect internet cable
2. Install firefox 56.0 (https://ftp.mozilla.org/pub/firefox/releases/56.0/) (Preferably change installation folder to "Firefox 56")
3. Disable auto-update in firefox 56.0
3.1. Reconnect internet cable
4. Install greaseMonkey version 3.17 (http://filepony.de/download-greasemonkey...rver-10117.html or http://filepony.de/dl-Z3JlYXNlbW9ua2V5LT...nkey-3.17-fx.zi)
5. Do this in THE CORRECT ORDER.
5.1. Install the function helper script (https://github.com/linus--tux/GMscripts_...nctions.user.js) (right click raw in github, then "show source code", you should have a bar on top that says "install this script")
5.2. Install your preferred language pack (https://github.com/linus--tux/GMscripts_...anguage%20Packs)
5.3. Install the berater script (https://github.com/linus--tux/GMscripts_...Berater.user.js)
5.4. Install the automat script (https://github.com/linus--tux/GMscripts_...Automat.user.js)
6. Open script window in firefox (about:addons in address bar), then go to scripts
6.1. MAKE SURE that each script actually has code in it (Options, Edit This Script)
6.2. If nothing pops up, you need to specify text editor for greasemonkey to use (can be anything, notepad for example) (You can do this by right clicking on greasemonkey icon in your firefox window and going to greasemonkey settings, specify text editor)
6.3. If the script does not have code, go back to github (Raw, Show Source Code) and copy the code over to the text editor you specified, save and close
7. Enjoy!