Issue with SQL Server 2012 Reporting Services - sql-server

Question

Preface: Installed SQL Server 2016 RC0 and installed and configured Reporting Services all fine, thoughts maybe on potential conflicts with existing SSRS instances?
Issue with SQL Server 2012 Reporting Services, every time I navigate through the configuration manager to either the Web Service URL or the Report Manager URL, I get the following errors:
Report Manager URL returns
HTTP 500 error
Console when opening the Report Manager URL returns
SCRIPT16389: Unspecified error.
http_500.htm (1,1)
HTML1524: Invalid HTML5 DOCTYPE. Consider using the interoperable form
!DOCTYPE html
.http_500.htm (1,1)
Web Service URL returns
The version of the report server database is either in a format that
is not valid, or it cannot be read. The found version is 'C.0.9.45'.
The expected version is '162'. (rsInvalidReportServerDatabase) Get
Online Help
Console when opening the Web Service URL returns,
GET http://localhost:8085/ReportServer_MYREPORTS 500 (Server Error)
To try and resolve this, i've already tried adding RSExecRole to RoleMembers under both ReportServer$MyReports and ReportServer$MyReportsTempDB.
Also tried recreating ReportServer database under the Config Manager, but get the following error.
Generating Database Script - Error:
Microsoft.ReportingServices.WmiProvider.WMIProviderException: An error occurred when attempting to connect to the report server remote procedure call (RPC) end point.
I can confirm that both RPC services, SSRS Services are running with no problems, and also restarted these services multiple times.
I have realised that my ReportServer$MyReports is missing the DBUpgradeHistory table.
Any thoughts?

Answer 1

This will fix the issue right away:
delete from dbo.ServerUpgradeHistory where ServerVersion=[The wrong or upgraded version]

Answer 2

In my case, there was no "ServerUpgradeHistory" table. I needed to install SSRS 2012 on a machine that already had SSRS 2016 to do regression testing for a client that doesn't want to upgrade their system.
What I discovered is that there are SharePoint settings that SSRS installs even if you don't install SharePoint or SharePoint Plugins on your box.
Here's what fixed the problem for me:
Navigate your File Explorer to C:\Windows\assembly\GAC_MSIL\
Note there are many directories in here that have nothing to do with SSRS. We will just focus on seven directories that appear to be related to this problem.
Navigate to Policy.11.0.Microsoft.ReportingServices.Alerting
Enter the assembly directory. This is usually a series of digits followed by a hexadecimal identifier.
E.G. 13.0.0.0__89845dcd8080cc91
This path will vary based on what is installed on the machine
Backup the config file in case you need to roll back changes
E.G. from a Command prompt: COPY *.config *.bak
Open the config file.
Look for the text in the newVersion attribute of the bindingRedirect tag:
<bindingRedirect oldVersion="11.0.0.0" newVersion="13.0.0.0">
Modify this to use "11.0.0.0"
<bindingRedirect oldVersion="11.0.0.0" newVersion="11.0.0.0">
Save your changes
Repeat steps 2 through 8 with the following subpaths:
Policy.11.0.Microsoft.ReportingServices.SharePoint.Common
Policy.11.0.Microsoft.ReportingServices.SharePoint.ObjectModel
Policy.11.0.Microsoft.ReportingServices.SharePoint.Server
Policy.11.0.Microsoft.ReportingServices.SharePoint.SharedService
Policy.11.0.Microsoft.ReportingServices.SharePoint12.Server
Policy.11.0.Microsoft.ReportingServices.SharePoint14.Server
Reboot your computer