Text turns red. Error writing to database

I was giving the hotel booking a try. Everything seems fine except I cant add bookings?
It reads as it should from database. If I manually change a booking in mysql, it will change on bookingsite as well. I can also move exisiting data, it saves as it should.
But when I try to enter a new booking, the text turns red and no data is written to database.
Can someone tell me whats wrong? No errors are written in log file eighter.
Problem seems to be insert, not update?

Hi,

Yes, if the text remains red, that means the created event is not saved in the database.

If you use PHP backend, you can download the demo here and compare backend implementation with your own app.
The same for ASP.NET MVC5.

Its the demo I am using?
I tried it on another webhost. It works there.

hmm… I don’t know which demo you use :slight_smile:
Please provide with details if you need my assistance.

I am using the demo you are refering to. https://dhtmlx.com/docs/products/demoApps/room-reservation-html5-js-php/?_ga=2.104802371.258627468.1562764918-1637533666.1559158426

I tried it on another server, it works fine there?
Is there some limits on version of php or something? I used same files, only changed host, db, user and pass in config.