UPDATE: Changes at the NCBI end have restored Blast functionality for all versions of SnapGene.
Recent changes to the NCBI Blast API have affected Blast functionality in SnapGene versions 7.2.0 and earlier.
These changes prevent the command Tools → Blast → Blast Selected Sequence... from sending the sequence to the appropriate Blast submission form in your default browser.
A fix for this issue has been implemented for SnapGene 7.2.1.
To restore Blast functionality, if you are using a subscription license, or a supported permanent license, then please update to SnapGene 7.2.1 when you are notified that it is available for installation.
Older versions of SnapGene are not supported for improvements or fixes. Users of older versions of SnapGene should copy their sequence from a SnapGene file and paste it into the appropriate Blast form.