It's hard to pinpoint the reason for the failure without direct access to the data. What AFNI version do you have? Not sure if updating the most recent version would help.
A couple of comments that are unrelated to the error.
> -model ‘A*B*C*D+E+(1+A+B|Subj)' \
> -qVars ‘C,D,E’ \
1) Make sure that all the 3 quantitative predictors C, D and E are properly centered. The default is mean centering.
2) If the interaction between C and D is of interest, I suggest that you create a separate variable, for example, called F. Center C and D first, and let F = C x D. Then, set the following:
-model ‘A*B*C+A*B*D+A*B*F+E+...' \
-qVars ‘C,D,F,E’ \
-qVarCenters '0,0,0,...' \
3) Are A, B, C, D and E within- or between-subject variables?
Gang
