This is a developing situation, so solutions are trickling in.
Some people are finding that even after updating NMM to v0.65.4 they still get a "script exception" message when installing some mods (such as UIO and MCM). This seems to be resolved by this suggestion from user ElysianMod:
Run NMM as an "Administrator privileges" account.
Go to NMM "Settings".
Enable "Add Shell Extensions for Supported File Types".
Then restart NMM.
-Dubious-
Holy molly, finally! I thought there is no hope left in this world! Thank you very much!
NMM "An exception occured in the script" [New Vegas]
in Mod Troubleshooting
Posted
Holy molly, finally! I thought there is no hope left in this world! Thank you very much!