from MegaTraveller Starship Operator’s Manual, p14

Misjumps: Sometimes, despite all precautions, something goes wrong with a jump transition, and a misjump occurs.

Apart from gravitational perturbations, the second most common cause of misjumps is contaminated fuel. On rare occasions, an unusual gas mix in the fuel causes the jump fusion power plant to load the zuchai crystals with a charge that is ever-so-slightly skewed, and a misjump results.

Misjumps can be classified by their effects: temporal, spatial, and combined. Each is dangerous and can result in the loss of the ship or crew, even if destruction at the time of jump transition is avoided.

In a temporal misjump, the craft reaches the intended destination point, but a Jump Time Duration Error occurs (also called a Jump Relativity Error). In such cases, the amount of time the craft remains in jumpspace may vary from 40 to 160 percent of normal. In many cases, a temporal misjump is nothing more than an inconvenience to the passengers and crew. In fact, it is possible for such a misjump to bring the ship to its destination ahead of schedule.
However, in extreme cases, the voyage may take so long that supplies dwindle and life support or fuel reserves fail. When this happens, the ship emerges from jumpspace with no survivors.

A spatial misjump forces the craft to arrive at a point in space other than its destination, although the time spent in jump is the normal 150 to 185 hours. Often, spatial misjumps are disastrous because there is no assurance that the craft will emerge from jumpspace anywhere near a star system. A ship which suddenly finds itself lost between the stars without a functional Jump Drive is almost certainly doomed.

A combined misjump is a dramatic event which causes the travellers to be subjected to combined effects of both a temporal and a spatial misjump.

and

Many feel a distinct “wrenching” sensation during Jump Transition, but few suffer any lasting effect. In rare cases, an individual may feel nauseated for a brief time following the Jump Transition. In cases of misjump, however, the instances of nausea and similar discomforts often increase. An unusual number of such complaints is taken very seriously, as it often is the first indication that a misjump has occurred.

from Mongoose Starship Operator’s Manual, p82

MISJUMPS Throughout Charted Space, many thousands of jumps take place every day without incident. Despite the concerns of a few paranoid souls who find the strange nature of jumpspace abhorrent and refuse to step aboard a ship that ventured into jumpspace, let alone enter themselves, the Jump Drive has proven a reliable technology in use for over ten millennia. It is entirely possible to live, work and die aboard a starship without ever encountering unexpected behaviour.

However, there are always exceptions. Called misjumps, these are a constant risk for starship crews, one that any captain wishing to keep their ship and crew intact will make great efforts to avoid. These efforts are mostly successful; the vast majority of misjumps are due to faulty equipment, unrefined fuel, early jumps or operator error. Nonetheless, it is occasionally possible for even the best-maintained ship with the finest crew to suffer from the capricious whims of jumpspace. A crew’s helplessness makes misjumps worse, as when one strikes there is little recourse but to glare at the Astrogator and hope for a safe emergence.

p84

An important fact about jump limits and anti-jump weaponry is that they only prevent safe jumps, not jumps in general. A target ship can choose to override warnings and engage its Jump Drive in a planetside docking bay, low orbit or within a Jump Damper Field and will vanish as normal. The chances of this misjump being survivable are almost zero. Even if it is, scatter will likely throw the victim into an empty parsec. If facing what they believe is certain death or a fate worse than death, some captains and crews will choose this as it beats the alternative and death by Jump-Field-induced disintegration is generally believed to be swift and painless.