I upgraded from Wordpress 4.8 (I think) to Classicpress beta1, later beta2 and now rc1. The first upgrade to CP was done by the plugin and worked fine. Now in beta1, 2 and now rc1 I get this message in the update-section:
Unable to determine whether a ClassicPress update is available.
You may be running a customized build of ClassicPress, or your server may be having internet connectivity problems.
This happens only on one of my 5 pages running Classicpress. All have done the same migration path.
How can I debug this?
Expected behavior
update should work or show that no update is available
Current behavior
I get the message that I run a customized build - see above.
If you already have ClassicPress beta 1 or 2 installed then you do not need a plug in for migration
the update is done in the admin panel of your ClassicPress.
Open the update page and upgrade to 1.0.0-rc1
Maybe it was a bit unclear what I mean: I did the first upgrade using the plugin, all others of course I wanted to do with the function you showed me. This worked for 4 of my installations, but in one I always get this screen (it is the same when a new version is out):
