I'm still having trouble with the dissolve tool and I've tried all of the solutions offered here including moving the process from the background and repairing the geography. I've also tried amending the spatial index and narrowing the dissolve area down considerably.
Is there anything that I'm missing?
Right now when I run the tool, it jumps right to 33% complete and stalls out. If I wait for an hour or so it gives me the 99999 error (edited to clarify, I am also getting the Invalid Topology error). I'm doing this project for work and waiting an hour each time isn't working for me (or my boss) anymore.