“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

I was also facing the same issue ,but now resolved this issue . I have used 2 foreachloop and 2 file system task in my package ,In First loop i'm assigning the values of excel fully qualified to a variable and same variable I was using in Second loop that is why this issue was coming. I have created another variable for second loop and assign that variable value into 2nd file system taks. Initially i was using only one variable as a source in both file system task,Now created 2 variable and issue is resolved. Please refer the sanpshot to see the details in snapshot.