[Plugin: Booking Calendar] Does this work on any THEME

Hello,
Yes, this plugin have to work with any theme, which is not generate a JavaScript errors on client or admin side of site. And themes have to be done with support of WordPress standards, like using the shortcodes like this
<?php wp_head();? ?>
and so on.

what would you say to this:
Warning: Invalid argument supplied for foreach() in /home/whistler/public_html/wp-content/plugins/booking.premium.plus.3.0/include/wpdev-premium-plus.php on line 545

Warning: Cannot modify header information – headers already sent by (output started at /home/whistler/public_html/wp-content/plugins/booking.premium.plus.3.0/include/wpdev-premium-plus.php:545) in /home/whistler/public_html/wp-includes/pluggable.php on line 927

as well on a page that has a booking calendar on it i get this:
Warning: Invalid argument supplied for foreach() in /home/whistler/public_html/wp-content/plugins/booking.premium.plus.3.0/include/wpdev-premium-plus.php on line 545

This is on line 545:
foreach ($booking_forms_extended as $value) {

i have gotten blown off every time i ask for mods or help from the developer.. if anyone can help it would be appreciated

Hello,
Probably you are have inside of the titles (or content) of the custom booking forms the characters, which is not excepted.
So please try to delete your custom form and then create new one but using the simple title for these booking forms (without umlauts, or % characters and so on…)