MultiMC version: Any (So far)
Operating System: Any
"Added instance 'Wurst Client for Minecraft 1.11'"
Try to add a custom client like wurst...
You cant.
Not EVERY version comes with a .dat file...
None...
I want my wurst!
Install the Wurst jar file as a jar mod in the Versions page.
Actually hacked clients are supposed to be their own version that you select. You add a folder to your versions list and select it from your profile screen as seen in this screenshot.

That's definitely not supposed to work in MultiMC.
Ever.
Just to clarify:
Installing and playing the wurstclient/any custom client i have met so far on MultiMC is possible, either by changing the main jar to the custom jar or by adding the custom jar as jar mod.
You do not have custom client versions to choose via gui like in the vanilla launcher, because MultiMC manages versions very differently than vanilla (and much better imo).
@DaveyL2013
The simplest way (i know) to install wurstclient on MultiMC:
You can Install the Liquidbounce Mod
Download: https://liquidbounce.net/
You have to intsl Forge!!
Have Fun 馃憤
This is seriously outdated.
If you actually have a replacement jar, you can replace the jar on the versions page.
Wurst is now a plain old mod I think.
Closing.
I was installing wurst for 1.8 so had to use its old version and @QulmUfu saved me! Thx!
Wurst is a hack client and MMC does not support hacking and abusing of others.
Most helpful comment
Ever.