Mongodb Not Restarting with Collections, WiredTiger.wt may be corrupt
There's now an official repair option that worked for me after a sudden computer shutdown https://docs.mongodb.com/manual/tutorial/recover-data-following-unexpected-shutdown/


Create a backup copy of the data files in the --dbpath
Start mongod with --repair

mongod --dbpath /data/db --repair
Upon completion, the dbpath should contain the repaired data files and
an empty mongod.lock

The collections were repaired without data loss.