Error message

[frailer]

Anyone seen this one? 'Unable to hold separation due to Invalid Data'.

Had output 1x4 col set a few hours before. Brought in replacement page...was the only change. Rest of the job to be plated. The error message occurred at the last step, when verifying which seps to release. On the one job only, so not a 'setter~XMF communication problem..
Resolved after some toying around, by re-rendering whole job. Am guessing a one-off corruption which I won't see again for another year.