PenciDesign replied
Hi,
As I checked from my-end, the RSS feed from our theme works fine:
https://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fsoledad.pencidesign.com%2Ffeed%2F
I think you have a plugin that caused this issue. I think that's from Jetpack plugin you're using.
I hear too many posts ( on wordpress.org ) about this issue from Jetpack. Example:
https://wordpress.com/forums/topic/jetpack-causing-feed-to-invalidate-error-500/
So, please try to deactivate all plugins ( except plugins come from the theme ) and try it again. If it works, let's enable each plugin to check what's plugin caused this issue.
Note: After deactivating the plugins, if you don't see the RSS feed update, maybe you need to wait for 12 hours and try it again because the RSS feed from WordPress can be caching to 12 hours. ( It's caching from WordPress itself )
Best Regards,
PenciDesign