Hi,
the error message just tells you that there has been a problem during the numerical 2nd derivative calculation, and the resulting Hessian file has not been created. The cause can come in many ways. Non-converged single-point energy calculations or, if excited states are used, TDDFT instabilities if you are near a conical intersection, or something else...
I'd recommend to contact the support team to find out what happened in your case, because without inspection of the individual jobs in the numforce/KraftWerk directory it is not possible to find the reason for the failure.
It often helps to look at the KraftWerk directory and check if there are log or results files with zero length.
Regards,
Uwe