Welcome to the forum @svalen.
Please can you paste your terminal output as text.
Before deleting the sock file, one should always confirm that no processes related to the given CryoSPARC instance are running, keeping in mind that a computer can run multiple CryoSPARC instances (if certain requirements are met). For this purpose: under the Linux account that runs CryoSPARC processes, run
cryosparcm stop
ps xww | grep -e cryosparc -e mongo
and kill (not kill -9) processes related to the given CryoSPARC instance, but not processes related to other CryoSPARC instances that may also be running on the computer.
For confirmation that no more relevant processes are running, again:
ps xww | grep -e cryosparc -e mongo
Only then should sock files belonging to the given CryoSPARC instance be removed.
Does this help?