Few weeks ago, during round #429, I've run into a Runtime Error when submitting any valid Scala solution. Today I've tried to submit some solutions, and had the same issue again (30041665). Also, I found that more Scala users had the same runtime issue in the last few rounds (eg., 29977952, 29706237 and more).
The error message is
java.lang.NoClassDefFoundError: scala/App$class. Probably this could be caused by Scala standard library missing from the classpath.
I (and, I believe, other Scala users) would appreciate if this could be fixed. Until then, unfortunately, Scala is not usable on Codeforces :(