Files do not open on reader.

I bought a used reader in ebay. Manufacturer: RockChip V 1.0.5.  I authorised the reader and i can download book on it. I can oped them with the PC but not with the reader. Message: File open failed or Invalid active info.  I found out that this reader is not listed among the supported readers. Can i do something or do i  have to throw it in  the garbage?