Hi,
what have you changed in your program? This 2nd SELECT works fine, because you're accessing with VBRK-VBELN (primary key) = i_vbfa-vbeln.
The 1st SELECT starts with VBRP-AUBEL for which you need an active secondary index on VBRP for field AUBEL and you have to start with VBRP.
Regards,
Klaus