All the themes i wanted to preview before i install is not showing on the right hand screen. IS there a way to fix this? I already removed all plugins, i am starting new.
You have entered the domain without https:// in the WordPress backend under Settings > General. However, you are obviously loading the page via https://. This could cause your browser to block the connection as non-encrypted data is being loaded.
Therefore, adjust the domain under Settings > General. The preview of themes should then also work (and many other things too).
I am running the wordpress install on my synology nas via webstation and the domain is on cloudflare. When i remove the proxy it removes the https:// and it work without it.
I already set Cloudflare SSL to full and it worked! The preview theme is showing now. I just encountered new warnings with WP when i do a health check. Will this be a problem?
Very nice that it worked out. I see CloudFlare as a possible explanation for the new messages. WordPress is trying to send a request and is not reaching its destination through this upstream service. I would recommend that you either deactivate CloudFlare temporarily to rule this out as the cause or write to CloudFlare support.