Visual Studio 2015: Disable Control+Click Navigation
I found my solution in the "Options - Text Editor - General" settings. This was on VS 2017 thou.
To disable navigation to symbol definitions in VS2015, this one worked for me.
With Resharper Ultimate 2016.3.1, I could fix the issue by disabling "Rich mouse navigation in the editor". It can be found in Resharper Options window, under Environment > Search & Navigation. Maybe updating Resharper could solve the issue.
Also, Productivity Power Tools is not installed on my machine.