You cannot login to Smart Materials, only this message appears:
'The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.'
This could be caused if the Microsoft Monitoring Agent is installed and running on the application server, because the tool is conflicting with some IIS features and thus impacting the Smart Materials application.
Check the Windows Event Log on the server, if it shows the following Event ID 1000 error:
Log Name: Application
Source: Application Error
Date: 24.02.2021 10:42:30
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer:
Description:
Faulting application name: w3wp.exe, version: 8.0.9200.16384, time stamp: 0x50108835
Faulting module name: PerfMon64.dll, version: 8.0.10918.0, time stamp: 0x577fd168
Exception code: 0xc0000409
Fault offset: 0x0000000000149794
Faulting process id: 0x2c38
Faulting application start time: 0x01d24405d195eb6a
Faulting application path: c:\windows\system32\inetsrv\w3wp.exe
Faulting module path: C:\Program Files\Microsoft Monitoring Agent\Agent\APMDOTNETAgent\V8.0.10918.0\PerfMon64.dll
Solution:
Uninstall Microsoft Monitoring Agent.