Tree view problem

I have just started using Megan, so I am not sure if the picture I see is OK, but seems like no. What could be the problem?
I have blasted a set of sequences from the metagenomic dataset against viruses taxid and loaded blast output files into Megan for the taxonomy tree visualization.
Best regards,

Please take a look in the message window. This tree view indicates that something went wrong and the message window will contain some error messages