The following webpage contains your manual:
http://wis.max-ltd.co.jp/int/pdf/o_manual/ER1500_ce.pdf
On page 21 your error code is explained as being one of these two circumstances:
4 printings have already been completed in one day, and/or
Improper print was made by manual operation.
Hope this helps- I didn't see any explanation of correction for this condition, so you might contact support if you cannot correct it.
Good luck, and hope this helps.