Uninstalled 1st time as in... First time booting up Logic after update El Cap -> Sierra, Logic started to validate all the plug-ins. Very quickly, but the usual routing. Why quick? auvaltool failed to open each and every 3rd party plugin. Using the plug-in manager within Logic gives the error messages visibly.
Uninstalled 2nd time as in... Actually going and deleting the cache file and directory. Reboot. Start Logic, it exhibits same behavior as above, with same result. I have the legit auvaltool saved from the early el cap beta days as a year ago we all had a similar problem, but not the same...
This is the actual output of trying to validate a plug-in:
Plug-ins, the same ones, work fine in Live by the way...
validating Audio Unit Omnisphere by Spectrasonics:
AU Validation Tool
Version: 1.6.1a1
Copyright 2003-2013, Apple Inc. All Rights Reserved.
Specify -h (-help) for command options
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VALIDATING AUDIO UNIT: 'aumu' - 'Ambr' - 'GOSW'
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ERROR: Cannot get Component's Name strings
ERROR: Error from retrieving Component Version: -50
* * FAIL
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TESTING OPEN TIMES:
FATAL ERROR: didn't find the component
validation result: couldn't be opened