The declared error is related to the PDF export, which is expected in case of incorrect dates. In FineReader Engine 12 R3 and newer, the creation and modification dates can be viewed and changed. For that, only the dates in correct format can be written into the documents. In case of the error, the date should be specified in a correct format or the writing mode should be changed (WriteCreationDate property of the DocumentContentInfoWritingParams Object).
The output document must have valid format: D:YYYYMMDDHHmmSSOHH'mm, as specified by the PDF 2.0 standard. Additional information could be found in the FineReader Engine Developer's Help file: Specifications >What's new > Export.