hfss antenna design error

try your solution setup with less no. of passes (10) and max delta (0.02). and sweep-interploating type -Linearstep

You need more free disk space, because your HDD is too full to store the solution fields.

HFSS is notorious for needing lot's of computer resources. In some cases you may be able to reduce the detail in your model. Usually that is not the case. Symmetry planes may help a bit but you probably want a bigger computer. RAM is your friend. So are more cores.

Increasing computing resources is always the best solution to have precise simulations with HFSS.
But if you need rough estimates and results you can go with smaller mesh.
Mesh definition is always very crucial to get correct results and no to burden your computational sources.
you can start with coarse mesh and check the results and then can go for finer mesh if needed and then take advantage of symmetry planes.
If doing all this does not solve your issue then there is no else option but to go for more RAM