Mike,
I have an idea where this might come from. You probably did an upgrade.
in this particular case there are some database changes(I know we promised no DB changes in Nightly Builds

). In the SQL folder of the install file there is an entry called
upgrade_1.11.11_to_1.11.12.sql.
Apply this manually to the database and you will be fine.
If this is too much, do a complete deinstall and install a clean version of the latest Nightly Build.
Good luck,