OMCQ....System message

Hi All,

Goods Issue to STO PO, I am getting below message.[I have already issued the STO qty].

"Document 0000000273 does not contain any selectable items." The message NO for this is Message no. M7064

But my concern is from where i am getting this message. Otherwise where this messages is maintained...I checked OMCQ..its not there.

Thanks & Regards