The old version was FANTASTIC!!

The new version doesn't work with my 3.17 scripts.
GM >=4 can't read scripts from the filesystem. So crap. So you have to use the crappy GM>=4 code editor.
The new GM also can't seem to access window variables, I can't be bothered to figure out why because I wouldn't want to use the GM4.x code editor. The Violentmonkey workaround I found online of serving the script from a local webserver sucks. It's a stupid and useless pain.

WTH!!!!!!!!!!!
This is the worst update EVER!!!!!
GM >=4 sucks and I'm sticking to 3.17.

If you want to run GM 3.17 this is what you need:
extract
https://download-installer.cdn.mozilla.net/pub/firefox/releases/56.0.2/linux-x86_64/en-ZA/firefox-56.0.2.tar.bz2
to /opt

run it like this
nohup /opt/firefox-56.0.2/firefox --no-remote -P foobar-profile 'http://foobar.com/' >/dev/null 2>&1 &

Go to preferences tell firefox to never update.

Disable GM 3.17 update
about:config
make new false boolean value named
extensions.{e4a8a97b-f2ed-450b-b12d-ee082ba24781}.update.enabled

Install GM 3.17
https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/versions/?page=1#version-3.17

什么情况？脚本大部分失效不说，插件连界面都简化没了，没有更新管理界面，每个脚本的开关还要点开二级菜单才行,只能装Tampermonkey了

It's a hurge work to change!
A lot's of people changed to Tampermonkey, so am I!
Bye~

4.x version broke the scripts.

Time to uninstall and change to working addon.

With the installation of 4.1, all my user scripts are gone, and there is no way to add a new one from the backups I had because the new user script button doesn't work 90% of the time (you have to click and wait up to 30 seconds to get it to pop up, and most of the time, it never does) and when it does, I can't save anything. This is on 57.

Where is the quality checking before breaking our web experience? Moving on to another scripting engine. Good grief.

all my scripts disappeared after updating to version 4.++

if this happened to you a fix is to reinstall the old version again

https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/versions/?page=1#version-3.17

you will find your scripts back :)

for developer you need to test you addon before releasing a major update

Do not use THIS. Use Tampermonkey - it's much better!!

Не используйте ЭТО. Используйте Tampermonkey - он гораздо лучше!!

I was forced to upgrade to GreaseMonkey 4.x with Firefox 56.0. My scripts stopped working. I wrote them, so I looked into fixing. I looked at the GreaseMonkey web site. I saw the general notice about the changes but could not find specifics. Didn't trust what I saw when I saw notes like "this script" hasn't been updated in years.

Fix up documentation. Provided example scripts with before and after changes.

Give warning if it doesn't work in Firefox 56. I tried Firefox 57, but that caused other problems for me.

Was able to turn off auto updated of GreasMonkey before downloading 3.17 version of GreaseMonkey. add ons > GreaseMonkey entry > more > click on off selector. See below for the link by Anonymous user e7bdbb to the download.

Robert
PS. There is snow on the ground as I write this :-(
PSS. FYI. Tampermonkey gave me a compile error on "for (var elmForm, i=0; elmForm=document.forms[i]; ++i)".

В один прекрасный день все сломалось. Непонятно, какие скрипты активны на какой странице, нет кнопки manage scripts, ни один скрипт не работает. Верните все, как было!!!
It was a dark and snowy night. The day couldn't get any worse, right? Where is my Manage scripts... button? Nothing works anymore! I can't get no heads, nor tails about which of my scripts are supposed to run on any particular site. All of them are displayed as active. The scripts that used to work just fine, they all stopped working. All of these damn ads are popping up EVERYWHERE! I'm close to a nervous breakdown, can't visit any of my favourite sites anymore without my eyes bleeding out. Damn it all and merry Christmas to ye all.

4.1 перестали работать скрипты

v4 fuked all scripts installed, time to move on to tampermonkey

fk 4.1

New version is completely broken. Use Tampermonkey instead.

The new version is absolute garbage. It updated on me just now and I lost all of my scripts. The exact same thing happened to Stylish!

So, I turned off automatic updates for Greasemonkey and installed version 3.17 and now everything is fine. I did a very similar thing for Stylish and that worked as well.

I will be avoiding all new versions of Greasemonkey.

4.x is as useless as Firefox 57.

thanks for the new awesome force-uninstall-gm feature. its great!!

I appreciated GM for a long time. Thank you for all the free work. I've to leave because GM does not fit to my needs anymore.

It somehow got force installed, I was holding off until it was working properly, and now every script is practically busted for reasons that are impossible to figure out because of lacking proper error reporting of cause. At this moment, it has become utterly useless. I have faith in the developer but this has been a truly bad update and now trying to figure out how to revert without losing everything.