Doing /locate stronghold in some single biomes causes an unexpected error

The Bug

Doing /locate stronghold in some single biome worlds cause an unexpected error for "Somehow tried to find structures for a placement that doesn't exits"

Affected Biomes

• Mangrove Swamp
• Deep Dark

Reproduce

• Create a single biome world with one of the biomes affected
• Do /locate stronghold

Observed Result

An unexpected error chat message appeared

Expected Result

You would find a stronghold or print a message saying cannot find stronghold