Operating system: Windows 7 SP1 64-bit
Graphics card: Geforce GTX 670
Broken: 2019.04.30 22:49
Short description of error
Sometimes, one node Substitution/Change to other Node, randomly. I can not give a .blend file, because this issue occurs randomly.
Node A1 >> Node A2 Node B1 >> Node B2 ...... Sometimes this change randomly like: Node A1 >> Node B2 Node B1 >> Node B2 ......
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).