Users testing SnapDeals on Snapnet are encouraged to verify their proof params before upgrading any sectors. To do so, run: b2sum /var/tmp/filecoin-proof-parameters/v28-empty-sector* (you may have to change the path to where your params are stored) and compare the results with the digest entries in this file.
If your digest does not match, the safest thing to do is to delete all proof param files before restarting your node and / or miner.