One of the suggestions I always give when a user has issues with the Plugin Registration Tool is to download first the latest CRM SDK.
The reason is simple: a new rollup installed or a CRM Online update can easily bring some changes with the previous versions of the tool, but if we use the latest version we can hope that the Plugin Registration Tool will work as expected.
Of course I never follow my suggestions, so it took me 2 weeks from the release of the latest CRM SDK (6.1) to discover the new Plugin Registration Tool!
It's easy to spot the switch from the ugly Windows Forms to WPF (Windows Presentation Foundation).
More important is the new position inside the SDK. Now the Plugin Registration Tool is located inside the folder SDK\Tools\PluginRegistration and not anymore inside the folder SDK\Bin.
Another change is the .NET framework required to run the tool, now you must have 4.5 installed:
But the main change is how the connection is handled, in the previous versions was necessary to insert the mysterious discovery url:
The new version is more user-friendly:
First it is necessary to specify the Deployment Type, between On-Premises, Online and Office 365.
For On-Premises is possible to specify the Authentication Source between Active Directory and Internet-facing deployment(IFD) and to use or not the default credentials.
For Online and Office 365, the user can select the Online Region (there is also the option Don't Know)
The functionality of the Plugin Registration Tool is still the same (register and update the plugins, install the profiler, ...) only the Properties box is positioned at the bottom (it is useful to check the assembly version)
A big welcome to the new Plugin Registration Tool!