Macros fail saying browser is already running

When I run the macros as a cron job, I get the error sometimes saying the browser is already running and asking to close it. Now, how can a cron job depend on state of browser ? Cron job should run independent of other jobs running. How am I supposed to fix this problem?

(1) Start a different profile

(2) Kill the browser before you start a new instance. This can be easily done by a shell script. Here is a Node.JS example.