                 fileName = @data.filename.trim()
                 message = @data.message
 
-                if fileName.length is 0 and @data.autoTail is 'on'
+                if fileName and fileName.length is 0 and @data.autoTail is 'on'
                     $(window.noFilenameError).removeClass('hide')
                     return false
 

            lastCommands = JSON.parse(localStorage.getItem(@localStorageCommandLineInputKeyPrefix + @id))
        catch e
            console.error('Could not parse previous commands JSON')
            lastCommands = [lastCommands.length - 1]
        vex.dialog.prompt
            message: "<h3>Run Task</h3>"
            input: runTemplate

                        fileName = @data.filename.trim()
                        commandLineInput = @data.commandLineInput.trim()

                        if fileName and fileName.length is 0 and @data.autoTail is 'on'
                            $(window.noFilenameError).removeClass('hide')
                            return false

