One of differences between previous version and version 4.0 is the expiry date. After that day, your cron jobs will expire and be deleted from your account.
So, how to renew your cron jobs? There are two ways, and all of them are FREE:
1. Edit and save your cron jobs.
When you save your cron jobs, the expiry date will be recalculated based on your account's limit.
For example, your account is Bronze, and your cron job is going to expire after 1 week.
After being edited and saved, your cron job will expire after 1 year (cron jobs every 5 minutes or more) or 3 months (cron jobs every minute or more).
2. Complete a survey.
You can complete a survey (which is totally FREE) and renew all of your cron jobs for 1 months.
Hope this helps :)