When you try start debugger from the Microsoft Dynamics NAV Development Environment, you can get the following error:
Microsoft.Dynamics.Nav.Client has stopped working.
This error indicates that the Microsoft Dynamics NAV Windows client cannot start. The error can occur when the version of development environment is different than the version of the Microsoft Dynamics NAV Windows client that debugger is starting. You can verify the versions by comparing the Application Version for the Microsoft Dynamics NAV Windows client that is shown in details section of the error dialog box with the version of the development environment.
Resolution
By default, the development environment starts the version of the Microsoft Dynamics NAV Windows client that was last installed. The Microsoft Dynamics NAV Windows client that is used by debugger is determined by the path that is specified by a protocol handler in the following registry key on the computer running the development environment:
HKEY_CLASSES_ROOT\DYNAMICSNAV\Shell\Open\Command
To work around this issue, before you start debugger, change the data value of the registry key entry to the path of the Microsoft Dynamics NAV Windows client that you want to use for debugging. For example, to start the Microsoft Dynamics NAV 2017 version of the the Microsoft Dynamics NAV Windows client, set the value to C:\Program Files (x86)\Microsoft Dynamics NAV\90\Microsoft.Dynamics.Nav.Client.exe -protocolhandler "%1".