(This bug is already resolved on my side, but perhaps you’d like to further investigate it to improve MainWP code.)
I have my MainWP dashboard in a separate WP installation, at a separate subdomain. There are 11 child sites connected. All WPs are the newest as of writing (6.5), same goes for MainWP plug-ins (dashboard and child).
Recently the dashboard ceased to connect to seven of my child sites; remaining four could be reached without a problem, and they were the most recent ones (I don’t know if it is relevant or not). When I tried to reconnect to my child sites, I was getting the same message:
Error message: error setting certificate file: /etc/ssl/certs/ca-certificates.crt
Some time later also this message appeared in the dashboard:
MainWP has detected that the OpenSSL.cnf file is not configured properly.
I tinkered with some MainWP settings (as previously they were in their default states; I tried out e.g. “Force IPv4”), but it didn’t make any difference.
I had a nice chat with MainWP help bot; it seemed very well informed and suggested that certificate packages should be re-installed on the server; it also suggested that I contact my host provider, which I did. I learned that /etc/ssl/certs folder was empty…
Later on I discovered that there was a problem with PHP session mechanism, not working on the server for some PHP versions, among other for 8.3.
When everything was still working, my MainWP dashboard was on PHP 8.1; when I upgraded it to PHP 8.3, it stopped to work. When I reverted to PHP 8.1, I was able to reconnect to all child sites (which are on different subdomains with different PHP versions).
Of course I’m not saying MainWP dashboard doesn’t work on PHP 8.3. All I’m saying is that I think that 1) MainWP dashboard doesn’t work when PHP sessions don’t work and 2) that the error message that is displayed is misleading.
I hope you will be able to confirm it and improve MainWP code.
Many thanks for your invaluable plug-in!