When activating a Frame Motor with a redsone signal the client will encounter an internal exception and disconnect from the server. The Frame Motor still works, but the client is sent a message with an invalid length.

Expected Behavior

The Frame Motor to activate and the client to not encounter an exception.

Current Behavior

The Frame Motor activates but the client is sent a message with an invalid length and causes an exception that disconnects the player. Any nearby players would likely get disconnected too.

Possible Solution

This may be a bug in ProjectRed
MrTJP/ProjectRed#1488

Steps to Reproduce

1. Must be playing on a dedicated server
2. Place a Frame Motor connected to a moveable structure
3. Power the Frame Motor with redstone

Log

Error in the client log:
https://gist.github.com/TigerWalts/2fe55ba84ffc0b1ec22b3db48091a662

Please link a full log or crash report.

• https://gist.github.com/TigerWalts/69f1d847c9f95bd24415ba42c942c176

The exception happens twice in this log, search for NetworkDispatcher exception to find the start of each.

Seems like it's been reported numerous times and still isn't fixed. Nothing we can do. Even if it was fixed we haven't been able to update Project Red due to incompatibilities.
https://github.com/MrTJP/ProjectRed/issues?utf8=%E2%9C%93&q=motor

The bug is not present in the latest release of ProjectRed 4.9.3.116.

Even if it was fixed we haven't been able to update Project Red due to incompatibilities.

Project red has been updated since it finally came with a newer update. I would suggest updating the modpack and seeing if that fixes it.