“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 had the same problem. Fix which worked for me:

Root Cause: I had created the variable and used it inside "Data Flow" to hold value of "Row Count". After this, I was trying to use this variable in "control Flow" > "Script Task". It did not work and gave me same error as posted.

Fix: I created the variables and used in "Script Task". After it got used in script task, I assigned the value of Row Count in Data Flow > Row Count.

It looks strange to me, but it worked :)