Hi Andy,
if "stucking requests processing" problem detect in dispatcher queue, then "Request handling without progress" error will occurs.
system will also write warning "potential request processing problem detected" within last 300 checks.
system restart will solve all the problem.
if the issue still persists and you want to know root cause, a complete dispatcher trace log (dev_disp) and dpmon results will be helpful.
Thanks and best regards,
Shi