We are using ImmersiveRailroading-1.7.3_1.12.2 on a server. The server generates these reports. Typically when a train goes over an augment.

[Server thread/warn] [minecraft/tileEntity]: Skipping BlockEntity with id
[Server thread/warn] [universalmodcore]: BAD TE DATA [controlMode: 0,parent:(x:0,Y:0,Z:-2), railHeight:0.0f,flexible:1b,snowLayers:0,coupleMode:0,version:3,redstoneMode:0,height:0.0f)

What are the causes or cures?

This can also be caused by the trafficcontrol mod, this is something I've had experience with.

This is known, the BAD TE DATA is pending an update release and has been patched.

Fixed in the latest test build, will be included in the next release.