upgrading from 11.5.3 to 12.1.0 do's and dont's

I always read the release note before any of the upgrade, and i think its very important. Here is link to 12.X release notes https://support.f5.com/kb/en-us/products/big-ip_asm/releasenotes/product/relnote-asm-12-1-0.html.

We are having 11.5.1 and thought of moving to 12.X but just on hold as as per information received from F5 support, the local logging is disabled in 12.X.X. However I still need to cross check. You should have your remote logging working flawlessly to engage into 12.X. My logging has got some issue as we are replacing our existing SIEM.

cheers