This started happening yesterday. On the first level, only one chest had loot and I am writing this as I play the mod now and the second level also has no loot.

Weird. Are you getting any errors in the logs when loading into a world / reloading the data packs?

No. The mod was fine the last time I used it. Here is the log
latest.log

Actually it looks like Dungeon Crawl is missing in your installation. The mod was installed before but isn't anymore.