Open Console.app and see exactly what is happening while you are trying this. Everything that happens on your Mac is time stamped. You may have to drill down to see any particular event.

One thing I would try is a Safe Boot. This rebuilds any corrupt paths and restores caches to defaults. If you see any alias icons that are generic instead of looking like the app or document, this is a symptom of corrupted paths. Every fresh install of High Sierra and Mojave I have done has exhibited this.

Boot with the Shift key held down. When your User account appears, log in. When desktop icons finish rebuilding, shut down and boot normally. This process takes awhile—a half hour on a Fusion drive is not unusual.

In the PPC days going back the the Mac+, this was called Rebuilding the Desktop and done the same way. I recommend doing it on all Macs once a year or whenever one sees generic alias icons.