A bad SWR
There is no general pass or fail mark when measuring VSWR. VSWR is measured as a ratio, i.e. 1:1 for no reflected power, 2:1, 3:1 and so forth. An open or a short circuit will be ∞:1.
Often VSWR meters will have a red calibration above 3:1 and this is probably the maximum you would want a transmitter to run with. A maximum of 2:1 would be better to prevent damage to the transmitter if it does not have protection on the output circuitry. Check the transmitter handbook in case there are guidelines on the maximum VSWR that the unit can work with.