Have there been accidents involving flight simulators?
I have been attempting to find information on this question for quite a while, and judging by the lack of answers, I am assuming that Zeus, in the comments to the question, is right: that accidents involving a flight simulator, to the extent that they are severe or sensational, are very rare. More often, accidents would be considered “workplace incidents” and would go unreported outside the company.
In Larry Milberry’s text The Story of CAE (2015), while discussing safety procedures and accidents in the development of flight simulation motion systems, several accidents did indeed happen, but none which involved injury:

There was a failure of a British Airways simulator where “a
malfunction drove the cockpit at maximum pitch-up velocity into the
end of travel, breaking the upper bearings and sending the simulator
to the floor.”
During the testing of the (never installed) Iranian CH-47 simulator
“there was a motion system failure. The simulators unusual vertical
configuration meant that any uncontrolled loss of hydraulic system
pressure would cause the flight compartment to lurch nose-down…
The potential for Murphy’s law to take over was there in spades, and
one day the interlocks did fail…”

In my pursuit of this question, working through historic newspapers, I have come across several tangentially related, though ultimately unsatisfactory, examples to my question: the 1967 oxygen fire in the Apollo 1 capsule simulator that killed 2 airmen (and 16 rabbits), an eerie repeat of the explosion which killed the 3 astronauts the Friday before; the 1991 B52 crash during the Gulf War which again was an &quot;eerie repeat&quot; of a “crash-in-the-box” during previous training; the 1991 deaths of two pilots “simulating” the attack on Pearl Harbor in Florida; the 2001 attempt by a man to open the emergency door mid-flight saying “it’s OK, we are just on a simulator”; and finally, many instances where flight simulators have been used to familiarize those with intent to hijack a plane.
Again, these are not what I am looking for, but they are the types of things you find when you start searching for this particular information. My sense is that there must be examples of accidents in flight simulators which have been significant but which, likely due to them being workplace accidents, did not receive media attention. Nonetheless, maybe this answer will help provoke the memory of others to contribute a more precise answer.