I was getting an error with my RSS Syndication component after I moved my site over to the new server. The error message I was getting was:
Error creating feed file, please check write permissions.

It turns out I just needed to set the right owner to the file and chmod the file to be writeable. The error message isn't very specific about which folder needs to be writeable and the post I found on joomla.org just said the cache folder. Most Joomla users would probably think of this as the folder named cache, used by Joomla, in the root of the joomla website. It turns out this wasn't the case - so I'm not sure if that's for a different version of the software or what. After searching on google for the error, I found a few more sites who were having the same error, but were also outputting some more information (in retrospect, I probably could have raised my php error setting). The folder is in /components/com_ds-syndicate/ and is called feed.

From your joomla root you can run the following commands (from Shell) to fix this. The other option is to use your ftp client to set the write permissions. Make sure to replace username with the username you want to own the file. You can try just setting the write permissions (777) first and if that doesnt work, then set the owner.

chmod 777 -fR components/com_ds-syndicate/feed
chown username -fR components/com_ds-syndicate/feed