Quote from MineCrak
Cart Mod v1.2.1 has been released!
This is a bug-fix version. v1.2 would crash if you tried to use the Capture Net on a mob that is not allowed to be captured with this net. With v1.2.1 you instead get the originally intended (and originally working ) message.
Everything will hopefully be smooth sailing from here on, but PLEASE do tell us right away if you find any other problems.
* This Release is dedicated to enderkirby for his very informative and useful Error Report, which led to this important bug-fix. Thanks!
You can [ Download ] the new version here or from the usual place in the OP. The link to v1.2 has been removed and destroyed, so don't worry about accidentally getting the wrong one now.
your welcome for the error report and sorry about the... spoiler