Hi!
This was a known issue with Multisite and WPML in previous versions. Please download the latest version from Codecanyon (currently 4.5.5) and install it safely by following the safe update instructions: https://wpdreams.gitbooks.io/ajax-search-pro-documentation/content/update_notes.html
The index should build up afterwards without any error messages.
Best,Ernest Marcinko
If you like my products, don't forget to rate them on codecanyon :)
