There are several other posts about both my problems but they show resolved with no information about any fixes.

When I first started realms I was able to back up my server but now for some reason it will not let me. I have tried everything from killing all my mobs in farms and destroying all my maps (found some in chests that would crash my game if I picked up).

Also at the same time my wither skeletons stopped spawning in my nether castle. I have explored new castles in the nether and they are broken also. I have spent hours running round with out any normal skeletons or wither skeletons; to be honest the only blaze that spawn are near spawners. Ghast I haven't noticed either but I won't lie I tunnel to avoid so can't confirm. I do get zombie pigmen, magma cubes, and occasional enderman.

I have had to reset my game mode to peaceful as some posts commented on but it never caused issues in the past. I was required to since there doesn't seem to be a mob cap (which I love) that has caused some issues when spawners left on in error and causing massive lag issues.

I am currently waiting on an email reply but it didn't include my wither issues and I was searching for forums to fix problems prior to submitting this