NIS 21.1.1 Update (from 21.1.0.18) fails on XP SP3

Following Tony W's instructions, the downloader finished and kicked off the update. Unfortunately it fails almost immediately with "A problem has occurred that needs your attention. Setup has detected an unknown incompatibility with a product on your system".

 

I couldn't find any hints or logs to suggest where the "incompatibility" exists

 

Any ideas?

 

Thanks in advance

 

 

NIS Upd Fail.JPG