Illegal Frame Error. Stack Problems. Sim-Crash at DND.

In the Console when I set the running Simulator in the dnd-mode

Error: Illegal Frame Error
Details: Failed invoking <symbol>
Stack:

And in the Error-Log:

!ENTRY org.eclipse.debug.core 4 125 2020-09-10 08:11:07.050
!MESSAGE Error logged from Debug Core:
!STACK 0
java.io.IOException: Pipe broken
    at java.io.PipedInputStream.read(Unknown Source)
    at java.io.PipedInputStream.read(Unknown Source)
    at java.io.BufferedInputStream.read1(Unknown Source)
    at java.io.BufferedInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at java.io.Reader.read(Unknown Source)
    at org.eclipse.debug.internal.core.OutputStreamMonitor.internalRead(OutputStreamMonitor.java:159)
    at org.eclipse.debug.internal.core.OutputStreamMonitor.read(OutputStreamMonitor.java:134)
    at java.lang.Thread.run(Unknown Source)

The same with SDK Version 3.1 and 3.2. I often have a TimeOut Message.

Thanks

More Infos

Thats too complicated for me. I can't remember that I changed anything important. But I have a WatchFace in the store and want to support it also in the future...

Thank you

And the Sim crashes when set the running watch to DND...