UE4.25.0 Could not initialize class org.codehaus.groovy.reflection.ReflectionCache

I had this same problem and took me a while to find something that worked for me.

I’m using 4.25 and have a clean install of Android Studio and Java.

From reading the bug reports on the gradle github - seems that the solution is to download JDK v. 8 - I did this, repointed my Unreal settings to here - and then it worked smoothly.

Hope this answer helps someone.