We tested the scenario and have managed to reproduce the same problem on our end. For the sake of correction, we have logged this problem in our issue tracking system. The ID of this issue is WORDSNET-22695. We will further look into the details of this problem and will keep you updated here on the status of correction. We apologize for your inconvenience.
@kngstr We have completed analyzing WORDSNET-23182 and concluded to close this issue as Not a Bug. The input document is corrupted. It has 72 cells per last row of the last table. We throw an exception in such case: System.InvalidOperationException : More than 63 cells per row is not supported for this file format. 63 is a maximum number of cells in row allowed in MS Word
Word2019 unable to open this document as well: WordErr.png (3.8 KB)