Is your full error this by any chance?

Unable to connect to Donut Team. Failed to connect:
LucasStuff.Radical.Simpsons.HitAndRun.ModLauncherSupport.CURL+Exception:
CURLE_SSL_CACERT_BADFILE

If so, open your "DLLs" folder and delete "cacert.pem".
No idea why it is sometimes corrupt.

Unable to connect to Donut Team. Failed to connect:
LucasStuff.Radical.Simpsons.HitAndRun.ModLauncherSupport.CURL+Exception:
CURLE_SSL_CACERT_BADFILE

Hi there, the site is indeed down at the moment, no idea why.
Try this alternative link for the launcher meantime.
(If the download doesn't work, use a firefox browser)
This launcher is hosted on our Discord, and has been retired from the official site because it was detected as a false positive.

Since there's no page I can send for you, here are a bunch of things you should make note of:
- You and your friend should have the same mods & mutators enabled to play together
- Multiplayer is very experimental and a lot of bugs are to be experienced
- It has no missions
- It has no traffic & pedestrians
I hope this helps, let me know if you have any issues with that launcher!

Hi there, the site is indeed down at the moment, no idea why.
Try this alternative link for the launcher meantime.
(If the download doesn't work, use a firefox browser)
This launcher is hosted on our Discord, and has been retired from the official site because it was detected as a false positive.

Since there's no page I can send for you, here are a bunch of things you should make note of:
- You and your friend should have the same mods & mutators enabled to play together
- Multiplayer is very experimental and a lot of bugs are to be experienced
- It has no missions
- It has no traffic & pedestrians
I hope this helps, let me know if you have any issues with that launcher!