ᐅ Dark yellow material is seeping out of the wall.

A wall in one of my properties has leaked a dark yellow material:

What material is this likely to be?

Looks like resin

What type of resin?

New build?
Old building?
On which wall and where exactly?
When and how was it constructed?
Inside?
Outside?
Hard, soft, porous, sticky?

Visually, it could be old, decomposed expanding foam that has melted due to heat exposure...

Assembly foam?