Since the update to PRTG version 18.104.22.1681 all http sensors which monitor a website via https get "HTTP/1.1 400 Bad Request" failure although the sites are up & running. The http sensors using regular http still work.
Only in one of the failing sensors I found this (might not be related to the https issue): Failed to establish secure connection [Step 4] Socket Error # 10060 Connection timed out. [Step 0] Socket Error # 11004 [Step 1] Socket Error # 11004 [Step 2] Socket Error # 11004 [Step 3] Socket Error # 11004 [Step 4] Socket Error # 11004 [Unsecure] IOHandler value is not valid
PRTG is running on Windows Server 2008 R2 (6.1.1 Build 7601 Service Pack 1) with only one local probe. .NET Framework Support: .NET 4 Framework ist installiert (Installiert: v2.0.50727 (2.0.50727.5420), v4\Client (4.5.51209), v4\Full (4.5.51209), v4.0\Client (22.214.171.124))
Unfortunately I don't know much about debugging sensors in PRTG. Is there a way, besides sniffing, to display the request the http sensor is generating? How can I check SSL handling is working properly?