Manual DPF not working

Hello,
Im a company driver and i drive a 09 mack CXU613, while at work today it asked to do a MANUAL REGEN, so i parked the truck and hit the button, but it didnt work, tried turning off the truck and all and still didnt work, now idk if its just a sensor or something more serious like cleaning the filter or something !?!?
Did anyone already had this issue before ?!?
Thanks !!

 

Thanks for the reply !!
Its a non DEF, It went away the next morning then it came back again in the afternoon, they bought the truck recently and it has about 470k miles, asked them if they knew if DPF was ever cleaned and they found out it wasnt, after 3 days of driving without doing the REGEN, light started blinking asking to do a URGENT REGEN, and i knew i couldnt be driving that truck anylonger. Took to a shop the next morning, DPF and DOC needs to be clean, it might need a new Dosing injector because i notice diesel coming out of the top and it has a hole on the exhaust pipe before the DPF, which i told them 2 months ago.