Failed to lock variable. The variable cannot be found

Question

In SSIS I am trying to use a file system task to move a file to an archive directory. This is what my task looks like - http://imgur.com/raPZIzL

When I run the package I get a failure on this task: Error: 0xC0014054 at File System Task: Failed to lock variable "\xxx\yyyy\Eligibility\SOURCE_ELIGIBILITY_IMPORT_0482014.CSV" for read access with error 0xC0010001 "The variable cannot be found. This occurs when an attempt is made to retrieve a variable from the Variables collection on a container during execution of the package, and the variable is not there. The variable name may have changed or the variable is not being created.".

I find it interesting that it's saying the variable is not found because the initial value of the variable is 'temp' (see screen shot) and then I set the value of the variable in a script task several steps before this task runs. So I know the variable exists and it has the proper value (I can open the file in the variable path). I just don't know why or how to get around this. I found the same message posted by others on the internet but none of the solutions worked for me. I don't see how this could be a race condition either, the script task which sets the value of the variable finishes a second or so before this task runs.

I have tried deleting the File System Task and recreating it, still get the error. I also restarted the computer thinking that might help but it didn't.

EDIT: more info...if I set DelayValidation from True to False, I get the same error before anything even runs, although this time it's complaining about the initial value of the variable before it has a chance to be set in code.

Here are the specific errors:

Error: 0xC0014054 at File System Task: Failed to lock variable "\XXX\YYYY\Eligibility\SOURCE_ELIGIBILITY_IMPORT_0482014.CSV" for read access with error 0xC0010001 "The variable cannot be found. This occurs when an attempt is made to retrieve a variable from the Variables collection on a container during execution of the package, and the variable is not there. The variable name may have changed or the variable is not being created.".

Error: 0xC002F304 at File System Task, File System Task: An error occurred with the following error message: "Failed to lock variable "\XXX\YYYY\Eligibility\SOURCE_ELIGIBILITY_IMPORT_0482014.CSV" for read access with error 0xC0010001 "The variable cannot be found. This occurs when an attempt is made to retrieve a variable from the Variables collection on a container during execution of the package, and the variable is not there. The variable name may have changed or the variable is not being created.". ".

Error: 0xC0014054 at File System Task: Failed to lock variable "\XXX\YYYY\Eligibility\Archive" for read access with error 0xC0010001 "The variable cannot be found. This occurs when an attempt is made to retrieve a variable from the Variables collection on a container during execution of the package, and the variable is not there. The variable name may have changed or the variable is not being created.".

Error: 0xC002F304 at File System Task, File System Task: An error occurred with the following error message: "Failed to lock variable "\XXX\YYYY\Eligibility\Archive" for read access with error 0xC0010001 "The variable cannot be found. This occurs when an attempt is made to retrieve a variable from the Variables collection on a container during execution of the package, and the variable is not there. The variable name may have changed or the variable is not being created.".

Answer 1

After much testing I found it was a problem with the Expressions. It seems every time I went into the expressions area and joined two variables together, that is when the problems started.

I was simply taking a base directory and adding "Archive" to the end, in the Expression builder area it would evaluate correctly but the package would fail. However, if I opened my File Task to get to the editor and I use the drop down list for the DestinationVariable property and select a variable from that list, it all worked fine.

So I ended up creating a few more variables (one for each file I am going to move) and then setting that value to the base directory + "Archive", then I selected that variable from the drop down list for the DestinationVariable property. Ran without errors.