Problems with 4.11 I didn't have with 4.8 - alising shadows.

I imported a simple one room model into 4.11 that I had in 4.8 used the same process but in 4.11 I get terrible aliasing on my shadows with the same lightmap settings, I didn’t get them in 4.8.
Any ideas?

Could you post some screen shot comparisons?

Lightmap at 2048 for walls and floor - 4.11. In 4.8 no aliasing.