Check your PHP/NGINX settings for the following...
Memory Limit: 128M
Post Max Size: 110M
Upload Max Filesize: 100M
Also, if using NGINX, make sure Maximum allowed HTTP request body size is set to 128MB or higher or use client_max_body_size 128M; in nginx.conf or NGINX directives (Plesk)...
That is the URL we used and we couldn't get it to work with xF 2.3.0 Beta 2 or any later version. Had to completely switch site back to xF 2.2.16 where the RSS works correctly with dlvr.it and Firefox shows the contents of the RSS feed when you click the icon instead of trying to download it.
What settings did you use in config.php to get redis to work on xF 2.3.0 without Xon's Redis Cache plugin, as the following settings I'm using result in a 500 error (altho the below code works for xf 2.2.x)....
# Redis
$config['cache']['enabled'] = true;
$config['cache']['sessions'] = true...
We tried to use the RSS feed link with dlvr.it and it says 'We can't find a working feed there' & 'We can't validate your feed: Content is an HTML Document, not an RSS/Atom feed'
Also, with Firefox, clicking the RSS Feed icon, downloads a file instead of opening the RSS feed in a new tab.
I get this error when trying to install XF 2.3.0 Beta 4 as a fresh install, at Step 2...
XF\Db\InvalidQueryException: MySQL statement prepare error [1064]: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''...