I have found this when I tried to install my ClickOnce app on my clean Windows XP VPC. EventType clr20r3, P1 tpclite.exe, P2 1.0.2446.22540, P3 450639e5, P4 tpclite, P5 1.0.2446.22540, P6 450639e5, P7 d0, P8 e9, P9 system.invalidoperationexce... P10 NIL. The scary and weird error I ever seen in ClickOnce app. The error occur because of the third ......