Quote from NoBias:
the update via platform is corrupted. [spoke with CS]
You need to close Tradestation completely.
Go to website / download platform / utilities
Download and run MSI repair [save then run]
Restart [never hurts]
Attempt to update from website
if didn't update, update from platform should work. [it worked for me]
>Updated to TradeStation 9.1 Version: 9.1 (Update 18) Date: 03/07/2013<
Will check to confirm location of MSI repair.