If you are seeing this error it probably means that you have not yet created the archives file (just referenced it). To remedy the situation, you can do one of the following:

1.) Publish a new post (this will cause smartArchives() to run, which will create/overwrite the archives file).

2.) Run the touch command from a shell (i.e., "touch archives.txt"). This will cause the error to go away, but the archives page still will not actually display anything until you publish a new post.

3.) Create a one-line PHP script that calls smartArchives() (e.g., <php smartArchives(); ?>) and access this file through your web browser. This obviously will run the smartArchives() function, which will create/overwrite the archives file.