Hi I have the dp-3510 and it is displaying the

The "fuser webb" is a part in your fusing unit that cleans the fusing rollers. There is no diagnoses needed. It is a Preventative Maintenance (PM) part that is replaced after the preset number of copies have been run. Some machines will eventually stop running so as to require you to get the maintenance done, some do not. You are however running the risk of damaging the fusing rollers if the webb runs out. If I were doing this maintenance the cost would be about $175 so use that as a guide.
Good Luck