i today during upgrade on my home test server to latest stable version I've encountered some problem.
first of all is the version reported, into the admin area it report the new version 6.8.9 but it don't exist, I can't download it.
After this error I've downloaded the latest stable version from the site the 6.8.8 version but after installation b2evolution version report is:
b2evolution version 6.8.8-stable released on 03/09/17
are running an outdated development version (6.8.8-stable-2017-03-09). Version 6.9.1-beta-2017-03-08 is available for download. It is strongly recommended that you upgrade.
something is really strange, you have a solution?
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Sorry about that, it was an typo on our server.
If you go to system > status it should update and tell you you are now running the latest stable version (6.8.8).
(6.9.1-beta does exist but is not considered a stable version. b2evo recommended it because it didn't recognize 6.8.8 as stable either, since we had that typo on the server.)