SSMS viewInfo error with no database list shown

PROBLEM

Opened SSMS 2012 and got error viewInfo. Unable to see database list.
On Refresh databases same error.

SOLUTION

For me it was to do a restore back 2 days

BACKGROUND

Others have had this.

Sysinternal Tools and filters to “Process Name is ssms.exe” and “Path contains AppData\Local\Temp”

It seemed to not be finding an Addin.

https://connect.microsoft.com/SQLServer/feedback/details/573771/value-cannot-be-null

https://github.com/TaoK/PoorMansTSqlFormatter/issues/48