Blank error message Message no. M7001 while doing MIGO

Hi All

I am performing goods receipt using MIGO tcode, everythings seems to be ok.

even after clicking on Check button system is giving doc is OK.but when i click on post button a error message appears with no text, its blank. the message number is M7001. if any one of u have idea about this please let me know.

Regrds

Yogesh