Then came in all the king's wise men: but they could not read the writing, nor make known to the king the interpretation thereof. They could not read the writing - Because it was in the pure Hebrew, not the Chaldean character. See below.
Related Commentaries of Daniel 5:8
Daniel 5:8
8 Then came in all the king's wise men: but they could not read the writing, nor make known to the king the interpretation thereof.