Website with DNN now only loads with the words "The service is unavailable."

There is no error message. There was no modules added and nothing was changed on the website from the admin side. I am wondering where I could start with this. When I research it online it suggests that it is a 503 webpage error and I have tried to recycle and restart application pool for the website.

I added a simple default.htm file because it is above the default.aspx and it loaded just fine when I went to the website so the IIS and everything seems to be set up properly.

I looked in the database at the event log and found the only exception that was recently shows says "Unable to create Lucene writer (lock file is in use). Please recycle AppPool in IIS to release lock."

I have recycled this and have shut it down and restarted it and it does not seem to help

Any help on what to do next would be helpful