I'm in the same boat - even after disabling all antivirus software we were still having the NoSuchFileException error. That's why I replied earlier, to see if anyone had any insights as to what particular application might cause it or to see if there was anything common in the environments of the people who are having this issue since it looks like it has been a few people.
We use Dynatrace for monitoring in our environment which seems like it might be the culprit. A search for 'Dynatrace classes.jsa' returns a few results which seem to describe similar behaviour to what we've been seeing here. I haven't been able to confirm this yet (I need to check before disabling it) but it seems to be the culprit so far - we're only having this issue on a subset of our gateways and all the ones we're having the issue on run Dynatrace (and the ones that aren't having this issue don't run Dynatrace).
Quick update: It looks like Dynatrace forcibly disables class data sharing to work around an old JDK bug: Loading...
