Access Gateway 4.2/Web Interface 4.2/Presentation Server 4 with latest hotfix rollup. I've recently implemented access gateway with AAC and it's providing access to the presentation server farm via web interface. It all works nicely except for one small issue. If I enable session reliablity I get a "Protocol Driver error". This occurs when attempting to launch an app from both the internal and external app. I've worked through most of http://support.citrix.com/article/CTX106531 (I skipped step 9 and anything about the xte service not starting as it starts just fine). Has anyone seen this issue before? James.