“Failed to lock variable” SSIS error

Question

I am getting an error randomly for a scheduled SSIS package which runs hourly. The funniest thing is that if I delete the checkpoint file and run the package again it works

Answer 1

It seems there is a variable is missing to the sequence container in the package may it needs to get from either other jobs or parent package. I think its the problem of either scope of the variable or the generation of variable values at run time.

thanks prav