I was having the same issue after I just upgraded Touchdesigner. Touchdesigner is now on 4.1.4 NDI. Resolume is on 4.0.1. I copied the Processing.NDI.Lib.x64 from the TouchDesigner099 bin in the program files folder and pasted it into the Resolume Arena Program Files folder.
That did the trick to get them both on the newest version.