Snapd:"stateengine.go:150: state ensure error"

System is running into hung state and becoming non responsive.
Not able to exactly identify the snapd error. It seems to be broken.

Nov 12 12:00:01 alpha CRON[38800]: (CRON) error (create tmpfile)
Nov 12 12:00:01 alpha CRON[38802]: (CRON) error (create tmpfile)
Nov 12 12:00:01 alpha CRON[38803]: (CRON) error (create tmpfile)
Nov 12 12:00:05 alpha snapd[1866]: stateengine.go:150: state ensure error: broken assertion storage, looking for model: broken assertion storage, cannot read assertion: open /var/lib/snapd/assertions/asserts-v0/model/16/generic/generic-classic/active: operation not permitted
Nov 12 12:03:17 alpha kernel: [866608.185742] INFO: task Collect FA Evnt:37459 blocked for more than 120 seconds.
Nov 12 12:03:17 alpha kernel: [866608.185772]       Tainted: G           OE    4.15.0-122-generic #124-Ubuntu

Would it possible require re-installation of Snapd ?

this looks like your disk is full, or re-mounted itself readonly during boot due to filesystem errors or something similar.

obviously even your cron daemon can not create tmp files either, there is something systemic going on with your OS installation, snapd likely just suffers from it the same way cron (and probably lots of other services) does.