I think a rebalancing is in order. The docking should prioritise real players over AI. If there are no available landing pads because of AI, one should be despawned to let the player through.
Yeah I get that problem sometimes myself. Usually spamming the docking request seems to work - eventually. Also make sure you are within the 7500 limit or the station will have no time for you.
I also noticed that (usually on outposts) that I will get docking clearance immediately after a ship (AI) leaves the station (maybe they are full and have no free landing pads).
I do agree though, a "Docking Denied - No Landing Pads Currently Available" etc would be a bit more informative. It has been shown - especially in Beta that network issues can also cause docking requests to be denied.
...... Also make sure you are within the 7500 limit or the station will have no time for you.
I can feel another dumb down coming.
"Dumb Down Coning" ? lol
EDIT: You ninja'd your spelling corrected before I posted.
Getting lots of docking denieds. Wasted 2 hours this evening shuttling between different places trying to get in.
The message needs to be more explicit.
As has been discussed before, the reason docking is denied is (usually) because all of the station's docking pads are occupied.
Either you could go to a different, less busy system, or try going into Solo play and see if there is a free slot there.