[NMusers] Compartment amounts, A(n), used as right hand side quantities in $PK

[xyan4]

Dear NMusers,

I am doing a simulation in NONMEM 7.2.0. I have an amount compartment 
A(2) on the right-hand side bioavailability F2 in $PK. I got an error 
messages as “… 555  WITH A(I), $OMEGA FOR ETAS IN $PK (OR $MSFI NPOP=N) 
MUST PRECEDE $PK”. In the control file, $OMEGA actually precede $PK. The 
thing is that the same simulation worked in NONMEM 6. It seems that the 
feature that “Compartment amounts, A(n), can be used as right hand side 
quantities in $PK……” has been implemented since NONMEM 6, see slide 16 
in http://www.cognigencorp.com/ecpag_org/2006/1_TomLudden_NONMEM_VI.pdf

I wonder what could cause this error in NONMEM 7.2, but not in NONMEM 6 
and how I can solve this in version 7.2.

Thanks for considering help!

Xiaoyu