Sometimes you have to uninstall managed solutions and there can be a lot of dependencies which you have to remove manually. In CRM 2013 a little pretty aspx page give us all the needed information.
Now with CRM 2015 this dialog is gone and you only get a simple text error message.
The Microsoft way: Use the SDK method ‘RetrieveDependenciesForUninstallRequest‘ to get the dependencies.
But there is an easier way via the old CRM 2013 aspx page.
What do you need?
At first find the solution GUID via SQL
Then you have to modify the URL
Copy the URL and past it to the browser.