Failed to compile project in Scala SDK 2.13

[Y2Nk4]

Expected Behavior

Compile project in Scala SDK 2.13

Current Behavior

While compiling the project with SDK 2.13, the compiler would throw illegal cyclic inheritance involving trait Iterable.

J:\Code\OfficeHours\src\main\scala\model\OfficeHoursServer.scala:18:58
illegal cyclic inheritance involving trait Iterable
  var usernameToSocket: Map[String, SocketIOClient] = Map()

Possible Solution

Switching Scala SDK back to 2.12.9 would work.

I saw some posts about the illegal cyclic inheritance error in StackOverflow, but not sure why, it might be an issue with Scala.

I recommend switching Scala SDK back to 2.12.9 if you meet the same issue before anyone figures out what causes the issue.