If the DB was a new DB that contained no tables, how could a table: mdl_files_reference - be full? Your other posting mentioned a different table/index was full!!!
Could be the type of Bluehost account you have is being restricted.
Bluehost has this page that 'explains' DB restrictions on shared accounts (you are sharing the DB server resources):
Here's what it says:
Database Size and Table Limits.
Occasionally databases grow faster then expected. This sustained growth can cause performance problems for any website. If ignored for long enough this can cause downtime. Our research shows that server performance degrades when the MySQL usage is over 1,000 tables and/or 3 GB on a single account or 1,000 tables and/or 2 GB on a single database. In order to ensure optimal performance for your account and the others in your shared hosting environment, please be wary of the following. 1. Run away error logs/sessions/cache tables in the database - delete excess non needed data.
2. Spam posts in a forum (phpbb, simple machines) - implement captcha to disable anonymous posting.
3. WordPress MU installations which allow anyone to create a blog.
4. Using blobs to store images.
According to above, one would have to turn off sessions recording in the DB right off the bat as Moodle uses DB for just about everything by default.
And another that might end up affecting:
"Shared Hosting Accounts
We only allow 50,000 inodes per cPanel account, because that is where we see optimal server performance. We do understand that not all of our customers can reduce their file count that far; for this reason this is a "Soft limit" meaning that while the limit is reached, you will still be able to upload files. Once the account exceeds 200,000 files then it will be in violation of our Terms of Service and can result in possible suspension."
Does anyone know the DB specs on a fresh 2.6 install? How many tables? Size of DB after initial install? or number of files?
BTW, even if one eventually is successful on a shared account, it could mean when the DB reaches those limits, Bluehost can/will shutdown your site - without notification [breaks terms of service agreement] (saw a posting in a Drupal forum concerning multiple Drupals that claims that's exactly what happened.).
Another thought ... this could also be the reason your old Moodle (a 2.3 version) 'stopped working due to some bug'. Still have a 2.3 running and there are no bugs in that version of Moodle that would cause it to stop working.
'spirit of sharing', Ken