Thank you for the fast reply. I tried this and it didn’t help though 
edit 1: I also tried re creating the anim BP from scratch. I noticed that the errors only occur if the anim BP is used by the hands mesh in my BP_MotionController. If I remove any reference to it the errors go away, which is strange.
edit 2: I just created a new blank VR project and the error isn’t happening.
edit 3: After deleting binaries, build, intermediate and saved, rebuilding the project in VS and fixing up redirectors some of the errors disappeared, but the nodes were still disappearing. I managed to create a new BP_MotionController and add a hand mesh with the Anim BP with no problems. I then tried to spawn this BP_MotionController from my VR pawn and now I get these errors:
edit 4: I have the project synced with my laptop (source control) so tried to implement it on there - same problem.
edit 5!!!: I tried spawning the BP_MotionController_2 from the level BP instead of from the VR Pawn and there’s no errors and no disappearing nodes. What on earth is going on??