I think the following screenshots illustrate the issue quite well:
It’s quite problematic for me, as sometimes you just recreate the “broken” node and the graph starts working again, but in others, other nodes along the way stop woking as well. Because of that, it sometimes takes hours to fix the problem.
For our company, this is problematic, as we have a library of graphs, loaded for use through Dynamo Player, which makes it impossible to troubleshoot for people, that are not Dynamo capable 
I would be really glad to know what is causing this, as it makes Dynamo graphs unrealiable for broader use within the company 
I have noticed there is a similar topic in the forum and I noticed it hasn’t reached a solution. Could it somehow be related to poor network connection? I have noticed it started happening quite often, once we started having issues with the server. I think prior to that I had never experienced this bug. So far, it is the only correlation I could think of, so any suggestions would be higly appreciated!
