The file was created/saved using a newer version of Maple. For example, in Maple 9.5 when opening a document created in Document Mode in Maple 10, the worksheet is blank.

Solution:

If you have access to the version of Maple on which this file was created, save a copy of it in .mws format, and then open the .mws file in your older version of Maple. Note that many features of the worksheet will not be available.

Worksheet Compatibility Issues