Cannot create site collection error object reference not set

When you create a new site collection from central admin, you get an error object referent not set.

This can happen for various reasons. 

It could be that the Alternate access mapping is set incorrectly or some orphan entries in your database or you’ve set content hub or environment is unstable and you notice Upgrade required when you navigate Central Admin > System Settings > Manage Servers

First thing tried was to use PowerShell to create site collection thought may be this slip the attention of the ward and could let me create site collection. Nope doesn’t work.

Checked for environment stability by navigating to Central Admin> System Settings > Manage Servers. Didn’t find any server with status upgrade required which means may be cumulative update was installed but psconfig wasn’t executed or failed.

Checked the alternate access mapping intranet, extranet and default urls were intact

For Content Hub, checked the Managed Metadata Proxy Service Application properties and unchecked the last two options that didn’t resolve the issue

Had a look a at ULS logs again and pointed something about the content database.

Change your central url from default to : http://centraladmin:portnumeber/_admin/DatabaseStatus.aspx and notice for any unusual databases or the ones not responding. Found that the one which wasn’t responding was orphan database added some time back but didn’t delete.

Run the following command in Powershell

orphanedDB = Get-SPDatabase | where{$_.Name -eq "Content Database Name"}
$orphanedDB.Delete()

Performed an IIS reset and voila now able to create site collection