SharePoint Farm Upgrade Fails – Configuration of SharePoint Products failed. Configuration must be performed before you use SharePoint Products

Had an issue In a Staging Environment at one of my client. I have installed August 2013 Cumulative package at SharePoint 2013 Staging Environment which is an basic single server setup. Tried several times through Configuration wizard and also PowerShell (PSConfig.exe –cmd upgrade –inplace b2b –wait –force) but no luck, continuously getting this error.

saying – " Configuration of SharePoint Products failed.  Configuration must be performed before you use SharePoint Products.  For further details, see the diagnostic log located at C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\LOGS\PSCDiagnostics_3_9_2011_14_18_42_272_416955813.log and the application event log. " in Both Wizard and Powershell.

Finally carried out below steps in order since it was suggested by someone on web.

1. Run This on CMD – “ stsadm -o setproperty -pn command-line-upgrade-running -pv Yes “ (more here – http://technet.microsoft.com/en-us/library/cc288357(v=office.12).aspx)

1. IIS Reset
2. Then Run "PSConfig.exe –cmd upgrade –inplace b2b –wait –force"

Above steps has saved the day of lot of people out there but For me it was worst since still the same error come out. Now in to the Wizard again. This time wizard bought a trick saying that one of my Web Application has Web.Config missing in IIS root folder at inetpub. When I dig in discovered that one web application missing it’s web.config file inside. Without waiting anymore, just removed the web application from the farm as luckily it was just a testing web app (investigation to be continued on who banged of the web.config )

After Removal of the Damaged Web App (Database still remains as it is in DBS) ran the Wizard again just to check. And yes It’s gone smoothly this time.

So if you face an similar kind of a scenario just check basic stuff first step by step if your Event viewer/SharePoint Log doesn’t contains much details on the occurrence.

1. Detach Databases from Web Applications if you have any migrated Web applications/Site Collections from any previous version of SharePoint and then run the upgrade
2. Custom Solutions also pops out these kind of issues. Even I have faced several times
3. And there may be damaged Web Applications in farm such as my scenario here (mostly Event viewer and SP Logs really helps)
4. Also sometimes after installation of CU/Service pack Wizard does not just become success in first run. If you prefer Wizard, just run it once again. I would recommend Shell Command (above) for this as it’s more reliable.