I have been having a log in problem on 2 realms I own, and another owned by a friend. This issue started yesterday. When attempting to log into a realm, it will display loading resource packs for about 8 seconds then display "unable to connect to world". This first occurred on my friends realm, none of us can log in. Then on my oldest realm, and finally this morning on my new realm. 

steps I have taken, which have not resolved the issue: delete and re-install Minecraft, restart my gaming console, restart my internet router, change character skin from personalized to "Steve".