R help - Apr 2010 - predict error code

Hello,
 
I am trying to calculate predicted values derived from one dataset into a
hypothetical dataset. I tried this line of code:
 
graphdata$fmgpredvalues <- predict(Acs250.3.4, graphdata)
 
and received the following error message:
 
ERROR: ZXend[1], drop = FALSE] %*%lmeFit$beta
 
I have made sure all variable names are the same between the two datasets and
all factors are appropriately labeled.
 
I appreciate any insight.
 
Thanks,
 
Brittany
 


      
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