Delete commons-io-2.11.0.jar (and all other obsolete jars for community commons) from the userlib
commons-lang3-3.11
failureaccess-1.0.1
guava-32.0.1-jre
j2objc-annotations-2.8
In addition to the perfect answer of Chris:
If you checked your userlib folder, didn't find the libraries and still receive the error; you potentially need to update your SCIM module too. The latest version for Mendix 9 was using commons-io 2.11, which conflicts too.
I ran into this myself today, so hopefully it will help someone in the future.