Management Point not responding to HTTP requests (error 500)

[FBF]

Just in case the posted solution didn't work for you, like it was my case:

In my case the "BgbServer.log" log file was reporting login errors of the MP server connecting to the Database (located at a different server). Error message:

ERROR: Can't retrieve SQL connection - Cannot open database "CM_XXX" requested by the login. The login failed

The thing was that I reinstalled the MP server using the same name. In the SCCM database (CM_XXX) at SQL Server the server's account logically was already defined, but since the MP server has been reinstalled, it is a different machine (probably because SQL Server is using the machine's SID).

The solution steps I took: 

1. Open SQL Server Management Studio and connect to the server which holds the SCCM database (CM_XXX).
2. Browse to "Databases\CM_XXX\Security\Users"
3. Edit the already existing MP server's account (for example "Domain\MPServer$") and take screenshots of every property (General, Owned Schemas, Membership, etc...)
4. Delete the already existing MP server's account (do not delete it from the "Security\Logins" section, it's not necessary)
5. Add the "Domain\MPServer$" account back to the "Databases\CM_XXX\Security\Users" section, setting the same same properties as shown in the screenshots you took in step 3.

After that, you don't have to do anything else, not even reboot, in a matter of minutes it will automatically start working and you should be able to successfully check MP status (http://<ServerName>/sms_mp/.sms_aut?mplist)

Hope this helps.