Multiple realms having issues since 1.12 .. Official Minecraft Community Realm and Joker Collison's Economy Realm.  OMCR is Creative and has been running sine DEC 2018. JCER is full survival and has been running since Nov 2017.  Both realms will have times when the game starts to struggle and then Kicks. Last week both realms Had chunk errors and had to be reverted to fix.  After reopening both realms got chunk errors a couple days later. We noticed when the game crashes the backup save file is smaller.  Normally the JCER is hovering around 4.6. In the photos it started going from 4.6 to 4.3..  Corruption time stamps according to the photo I Attached. 23HR 4269.79 (21:44:21)    1HR  4321.22 (19:25:54)