java.lang.noclassdeffounderror when running on 1.16.5

[elliothawkz2]

https://pastebin.com/w1rCkwpr Here is the log. Basically it won't start due to a java.lang.noclassdeffound error

[Corosauce]

needed coroutil, i used to have a cleaner message that pops up about this but it was lost in the sea of updates.