Steps to Reproduce:

1. Create a world with the seed -2044586705
2. /tp 1661 26 -37

Observed Results:
No spawner generates.

Expected Results:
A spawner should generate.

Original Description:
I found 5 separate dungeons in my world, but none of them had an actual spawner inside - might be to do with the fact that they were all connected to a mineshaft - I also dug around them to see whether the actual spawner was somewhere else, but it seemed to have not generated at all - it is an old world though, so could be to do with new updates corrupting certain things/chunks - the picture shows one of the dungeons without a spawner. Not all of the spawners are missing in my world though; there were still cave spider spawners where they were meant to be.