I recently re-installed Visual Studio due to some issues with the integration with Intel Parallel Studio. After reinstalling both, the integration issues are gone, but now for some reasons I have two issues. One is minor: automatic outlining has been disabled by default, and I have to re-enable it every time I start VS using Edit > Outlining > Begin Automatic Outlining (or something similar). Annoying, but at least it works.
The second issue however is that IntelliSense is not working. Under Edit > IntelliSense,  Toggle Completion Mode is grayed out. After reading the answer to Visual Studio C# IntelliSense not automatically displaying, I followed the instructions and went to Tools > Options > Text Editor > Fortran. However all three of the check boxes are grayed out. Is this a known issue and does anyone know how to fix it?