This error message is shown to people still having an everlasting premium license (premium legacy) and are using a version of qbase+ which they're not entitled to.

Only versions released before the end date of the license can be used. Downgrading to the latest version you're entitled to solves this error. You will be able to keep on using this version indefinitely.

How do I know what version I can use?

Login to your personal account

URL: https://www.qbaseplus.com

Browse to your license overview

Check your license type and end date

URL: https://www.qbaseplus.com/me/licenses

Check the qbase+ release dates

Version	Release date	Download
2.5.1	June 21, 2013
2.6	October 3, 2013
2.6.1	March 3, 2014
3.0	November 5, 2014
3.1	October 26, 2016

In this example, qbase+ 2.6.1 would be the latest version that can be used as it's the last one released before the end date of the license.