I just had a weird problem when loading a node material from a json file saved with the current version of NME. I get an deserialization error. It was on an existing material (created in a previous version of NME) that I have been using successfully and then I made a small change and saved from the current NME and it no longer worked. I compared the file to the previous version in my source control and worked out it was these lines that were added to the inputs of a VectorMerger block that caused the problem.
"isExposedOnFrame": true, "exposedPortPosition": -1
I am not sure how to reproduce this anywhere. Is it possible to choose the version of NME that you are using like you can choose the engine in the playground?