After these 45 days you can't download new product releases (released after your license expiry date). Also you will no longer be able to request support for your instance from support.atlassian.com or via email / phone.
You can find more info here:
After the first 12 months, your software maintenance will expire and you will no longer be able to receive technical support or software updates. Renewing your software maintenance is done purely at your discretion and can be renewed in advance of your maintenance expiration to ensure uninterrupted access to the support and software updates.
(oops, sorry) For server version, it'll carry on working, but you won't be supported, and you won't be able to upgrade to any version released after the end of your licence.
Two vulnerabilities have been published for Confluence Server and Data Center recently: March 20, 2019 CVE-2019-3395 / CVE-2019-3396 April 17, 2019 CVE-2019-3398 The goal of this article is...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events