Exception: mb_stripos(): Argument #1 ($haystack) must be of type string, array given

Hi,

I want to send a push notification to everyone who has a similar interest.

I am getting these users back as a list in var Profile1, then iterate through each item in the list to send each user a notification.

However, when I run and debug I get this error: Exception: mb_stripos(): Argument #1 ($haystack) must be of type string, array given

Any idea what I can do?