For anyone else having trouble with this, here’s how I resolved it:
Line 43 in wp-content/plugins/rss-post-importer/app/class-rss-post-importer.php reads:
'feeds_api_key' => sanitize_key($_POST['feeds_api_key'])
Since I am not a premium user, I don’t have an API key. There’s nothing posting as ‘feeds_api_key’, and this triggers the above notice.
To fix it, I commented that line out, and replaced it with:
'feeds_api_key' => ''
If you are going to use this for yourself, please note:
* Since I edited the plugin file directly, any upgrade may cause this edit to be overwritten.
* If I ever choose to upgrade, and use an API key, I must revert to the original code for the upgrade to take effect.
(* The reason I replaced the line, is because this index is used later on in the code. If you just comment it out, then the code will trigger the same notice on line 49.)
If you plan to upgrade eventually, here’s a better solution:
Add this code above line 42 (which reads: $settings = array(
):
`if ( isset($_POST[‘feeds_api_key’]) )
{
$feeds_api_key = sanitize_key($_POST[‘feeds_api_key’]);
}
else
{
$feeds_api_key = ”;
}`
and replace the code from line 43 with:
'feeds_api_key' => $feeds_api_key
This will first check if an API key was posted. If you have an API key, it will use that, and if not, it will replace the ‘undefined index’ with an empty string.
Good Luck!