This was a problem with the CDN having gotten stuck. Yesterday I uploaded the release twice, within a few seconds, because of a small typo. Unfortunately, the CDN holding the update files started delivering the update XML file from the first attempt, which has a different checksum than the version actually being delivered.
I have reset the CDN now and verified that, at least from three different locations across the world I can check from, delivers the correct information.
However, that's not the end of it. Joomla! also has its own cache for update information. This means that your sites have now cached the wrong update information for the next 6 to 24 hours. Therefore, you need to go to System, Update, Extensions and click on Check for Updates to tell Joomla! to forcibly reload that information from our CDN, ignoring Joomla's own cache.
Then, you can update Akeeba Backup.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
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