SSMS is crashing and SSMS Toolbar
It looks like your instance of Management Studio is either corrupt or is in need of repair. 

This could be for many reasons, including installing it on an unsupported version of Windows, or an unsupported version of .NET. I have previously seen problems like this when someone has installed Sql Server 2012 on Windows Server 2016 without enabling .NET 3.5 Runtime.

What I recommend you do, is to remove the version of SSMS that comes pre-packed with Sql Server 2012 and install the standalone version instead.

To uninstall your existing version of SSMS, follow the steps below:


Open Programs and Features (type appwiz.cpl in Run/CMD)
Locate Sql Server 2012 and select Uninstall/Change.
Go through the wizard, choosing the Sql Server instance you want to modify.
Untick Management Tools - Basic and Management Tools - Complete.
Click next to skip through all of the remaining steps.
Click finish to uninstall SSMS.


Once you have completely unsintalled the existing version of SSMS, go to Download Sql Server Management Studio (SSMS), then download and install the latest version.

As always, check that your system meets the requirements for SSMS before attempting the install.