I've noticed a few issues in my world that I think are being caused by the fact that it was created back in 2016. I've looked up some of these and noticed that they couldn't be reproduced and this is the reason why! My issues include:

A Witch Hut that doesn't exist anymore (MCPE-28541)

Some dogs that I can't interact with (MCPE-39371)

Ghasts that are flying around like crazy (MCPE-30588)

Zombie villagers wearing the wrong clothes (MCPE-45586)

Redstone not working around the edges of an Old World type (it worked before; not sure if this is related) (MCPE-34015)

The same music keeps playing in Survival (again, not sure if this is related; it worked before)

Purchased content doesn't transfer between Bedrock devices (MCPE-25371)