Getting (local) tBlastx working, error: Protein provided for nucleotide sequence

[benzle]

Any help would be much appreciated, I am trying to get tBlastx to work but not having any luck (error message and query in attached image).

I have a single amino acid sequence to "BLASTx" to a large list of nt sequences. If I run the same set under tBlastn, it works perfectly, so I should be able to use the exact same query and subject for tBlastx, right?

When I try, get get an error that a protein was used for nt, but why does it work for tblastn?

Thanks everyone

[ddb]

Perhaps you can give a few more details about what you are trying to achieve so that we can help advise the most suitable tools. At the moment page 3 of the blast guide might help with the search types and the input / database types (nucleotide/protein). tblastx expects a nucleotide as input and searches against a nucleotide database.