Difficult to open/close front door

[Wundingle]

Hi all,

Hope everyone is doing well.

We’ve lately found it increasingly difficult to open/close our front door and there seems to be a bit of resistance at the bottom. Looking closer, it looks like a patch of cement-like material that covers the metallic track part of the door frame. What is this and is it safe to chip away a bit to help the door move more freely?

Thanks in advance!

 

[Wundingle]

 

[freddiemercurystwin]

Peculiar, looks like leveling screed or similar, I can't see why that would be there. That said, if the door was working fine at some point then that suggests it's gradually dropped and needs adjusting.