On 29th October, 2018 Citrix has released XenApp 7.15 LTSR Cumulative Update 3. Any known issues reported specific to CU3 ?

Here you go, direct from Citrix.

https://docs.citrix.com/en-us/xenapp-and-xendesktop/7-15-ltsr/whats-new/known-issues.html

I wouldn't rush in to a CU from them, to be honest.

We had some issues that meant we were asked to put the then early release of CU2 on. It didn't fix the issues we were seeing but introduced a fair few more that no one else apparently was. We've ended up with private fixes that are going into CU3.

Either put it into a test/dev environment first or let others have the pain of early adoption.

I'd say the same with all fixes, such as from MS as well.

I have done two greenfield implementations with CU3 (manual provisioning, no MCS or PVS) with no issues (so far).

Yeah I'd agree greenfields is less of an issue and traditionally always has been for Citrix but unfortunately the places I work are always up to their ears in legacy systems.

I have only seen one issue reported in the Citrix support forums but that issue is typical for any upgrade, VDA upgrade/installation issues. That is not a big deal and Citrix provides a VDA Cleanup Utility if you do run into VDA upgrade issues.

Thank you.