looks like your lightmap might be too lowres which means there is not enough pixel space to describe what's going on. another probably cause is the pixel density between the door and the wall is different. try a 32x32 or 64x64 lightmap. if that doesn't work try to unify the pixel density between the door and wall. also…
Yes, Ive been there with this problem before. Anytime you have a flat plane meeting up directly with another flat plane you're almost always going to get a seam like that, no matter how perfect your lightmaps are.(I think it is possible to make it seamless if your lightmap pixels line up perfectly, but I found it more…