After upgrading from Eclipse Neon to Oxygen I noticed that I can no longer navigate around the code by clicking on definitions while holding the Ctrl key down. The indexer itself works fine, and I can still jump around by pressing F3 or using the context menu.
I am using Eclipse CDT with C++.
The following screenshot proves that the feature is enabled:
What am I missing?
You're probably running into bug 517610. Note the following workaround from the bug:
To work around the problem, you can disable the Change Log hyperlink by going to Window > Preferences > General > Editors > Text Editors > Hyperlinking, then untick "Changelog Detector".
The bug fix is scheduled for Oxygen.1, which will be released on September 27th 2017. Alternatively, you can update to the latest development build (6.1.0) of Linux Tools (which is the component that contained the bug) via the update site http://download.eclipse.org/linuxtools/update/
.