Question: solving a nonlinear differential equation

i had a 15 set of nonlinear PDEs,i convert them to nonlinear set of ODEs, i try to solve them using the command dsolve(numeric) , but when solving i face this erroe :

Error, (in DEtools/convertsys) numeric exception: division by zero

what should i do?the problem is in my equations ? or what?

with regards,thnx. 

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