Hello,
I followed the instructions below to manually install the blast_datatypes:

Manual Installation
===================

Normally you would install this via the Galaxy ToolShed, which would move
the provided blast.py file into a suitable location and process the
datatypes_conf.xml entry to be combined with your local configuration.

However, if you really want to this should work for a manual install. Add
the following line to the datatypes_conf.xml file in the Galaxy main folder:

   <datatype extension="blastxml" type="galaxy.datatypes.blast:BlastXml" mimetype="application/xml" display_in_upload="true"/>

Also create the file lib/galaxy/datatypes/blast.py by moving, copying or linking
the blast.py file provided in this tar-ball.  Finally add 'import blast' near
the start of file lib/galaxy/datatypes/registry.py (after the other import
lines).

=========================

I restarted my local Galaxy instance but still get this error.

WARNING:galaxy.datatypes.registry:Error appending sniffer for datatype 'galaxy.datatypes.xml:BlastXml' to sniff_order: 'module' object has no attribute 'BlastXml'


Any help would be much appreciated.
Thanks,
Liisa