I had configured galaxy with MySQL database and for some time it was working fine. But suddenly it started showing following warning whenever I start galaxy. 

".../galaxy-dist/eggs/SQLAlchemy-0.7.9-py2.6-linux-x86_64-ucs2.egg/sqlalchemy/sql/expression.py:1927: SAWarning: The IN-predicate on "request_type.id" was invoked with an empty sequence. This results in a contradiction, which nonetheless can be expensive to evaluate.  Consider alternative strategies for improved performance."

And now I am not able to upload any file. Please help me to resolve it.

Thanks