Next button not working

Hi,

if i click “Następny” (Next) button nothing is happening. I checked this: https://support.booking-wp-plugin.com/hc/en-us/articles/360021300659-Next-button-doesn-t-work-in-the-booking-form . Shedule in staff is enabled. But here is error i Settings > Logs.
Target: …tend/components/booking/InfoText.php:91
ERROR: Call to a member function getCategoryId() on boolean
Can You help me with that?
Tahank You

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