The first one was caused by this:
-- Entity being ticked --
Entity Type: minecraft:falling_block (net.minecraft.entity.item.EntityFallingBlock)
Entity ID: 1278
Entity Name: Falling Block
Entitys Exact location: 555,50, 33,97, 608,50
Entitys Block location: World: (555,33,608), Chunk: (at 11,2,0 in 34,38; contains blocks 544,0,608 to 559,255,623), Region: (1,1; contains chunks 32,32 to 63,63, blocks 512,0,512 to 1023,255,1023)
So this looks like a falling block has bugged out, if you have world edit, you should be able to delete it remotely.
The 2nd report, I have no idea what is wrong in that one.