I am new to the forum and hope I am putting this in the right place.

I am trying to remove the DRM from two PDF's but I am getting error messages (I have removed others and they are fine).

The error message for book 1 is:
Error: Dict required: 2698

The error message for book 2 is:
Error: Dict required: <PDFStream(None): raw= 11099, {'Filter':/FlateDecode 'Length': 11099, 'N': 200, 'Type': /ObjStm, 'First': 1940}>

Does anyone know what these mean and what I can do to unlock the books?

Thanks.