UGENE has certain primers format. It allows one to use some features, which are avaliable only if this format is being recognized. Examples of thes features:

• Create PCR Fragment,
• Primer-BLAST.

If you have a primer pair, which doesn't fit to this format, these features will be unavaliable for you. To fix this issue:

1. Select your own left and right primers.
2. Click right mouse button → Edit → Transform into a primer pair.
   After these steps are performed, a new primer pair, fit to UGENE format, will appear: