https://live.paloaltonetworks.com/t5/globalprotect-discussions/globalprotect-fails-during-pre-login-with-winhttpreceiveresponse/m-p/1260244#M7446 <DIV>GlobalProtect is unable to connect during the pre-login phase.</DIV> <DIV> <UL> <LI>Verified all required certificates are installed on the endpoint.</LI> <LI>Confirmed certificates are located in the appropriate certificate stores.</LI> <LI>Collected and reviewed: <UL> <LI>GlobalProtect logs</LI> <LI>TSF</LI> <LI>Firewall packet captures</LI> </UL> </LI> </UL> <DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3">We got the following error in PanGPS.log:2&nbsp;3(P5136-T8916)Debug(544): CPanHTTPSession::PostRequest: WinHttpReceiveResponse...4(P5136-T8916)Error(549): CPanHTTPSession::PostRequest: WinHttpReceiveResponse failed with error code 12152.5(P5136-T8916)Debug(1439): PostRequest error code=12152 (The server returned an invalid or unrecognized response)6(P5136-T8916)Debug(8698): prelogin to portal result is (null)7(P5136-T8916)Debug(9106): Failed to pre-login to the portal x.x.x.x with return value 12152 (The server returned an invalid or unrecognized response)</DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3">&nbsp;</DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3"> <DIV>I have not been able to identify a root cause from the available data. The failure occurs during communication between the GlobalProtect client and portal, and the connection does not progress beyond the pre-login stage.</DIV> <DIV>&nbsp;</DIV> <DIV> <DIV>Any guidance or similar experiences would be greatly appreciated.</DIV> <DIV>&nbsp;</DIV> <DIV> <DIV>Thank you.</DIV> </DIV> </DIV> </DIV> </DIV> </DIV> Tue, 28 Jul 2026 15:53:26 GMT R.Singh384240 2026-07-28T15:53:26Z https://live.paloaltonetworks.com/t5/globalprotect-discussions/globalprotect-fails-during-pre-login-with-winhttpreceiveresponse/m-p/1260244#M7446 <DIV>GlobalProtect is unable to connect during the pre-login phase.</DIV> <DIV> <UL> <LI>Verified all required certificates are installed on the endpoint.</LI> <LI>Confirmed certificates are located in the appropriate certificate stores.</LI> <LI>Collected and reviewed: <UL> <LI>GlobalProtect logs</LI> <LI>TSF</LI> <LI>Firewall packet captures</LI> </UL> </LI> </UL> <DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3">We got the following error in PanGPS.log:2&nbsp;3(P5136-T8916)Debug(544): CPanHTTPSession::PostRequest: WinHttpReceiveResponse...4(P5136-T8916)Error(549): CPanHTTPSession::PostRequest: WinHttpReceiveResponse failed with error code 12152.5(P5136-T8916)Debug(1439): PostRequest error code=12152 (The server returned an invalid or unrecognized response)6(P5136-T8916)Debug(8698): prelogin to portal result is (null)7(P5136-T8916)Debug(9106): Failed to pre-login to the portal x.x.x.x with return value 12152 (The server returned an invalid or unrecognized response)</DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3">&nbsp;</DIV> <DIV class="SimpleCodeViewer__codeLine__d34b0e82 SimpleCodeViewer__codeLineWrap__53d6e134" data-line-index="3"> <DIV>I have not been able to identify a root cause from the available data. The failure occurs during communication between the GlobalProtect client and portal, and the connection does not progress beyond the pre-login stage.</DIV> <DIV>&nbsp;</DIV> <DIV> <DIV>Any guidance or similar experiences would be greatly appreciated.</DIV> <DIV>&nbsp;</DIV> <DIV> <DIV>Thank you.</DIV> </DIV> </DIV> </DIV> </DIV> </DIV> Tue, 28 Jul 2026 15:53:26 GMT https://live.paloaltonetworks.com/t5/globalprotect-discussions/globalprotect-fails-during-pre-login-with-winhttpreceiveresponse/m-p/1260244#M7446 R.Singh384240 2026-07-28T15:53:26Z