[quote=443560:@Leonidas Brasileiro]Hello @Pietro Beccegato !
I saw in your demo that the issue is gone…
Hoe did you solve it?[/quote]
The issue is generate when you try to change a weblistbox column number but the weblistbox is not empty (without any rows).
You have to delete all rows, before change the column count. Be careful, because in xojo web applications, sometime the events sequence is not exactly the same of the instruction sequence wrote in the code. Instead using your code, make a test adding two buttons; the first one delete all rows and the second one change the column count and load data into the table. If, using the buttons, the problem not appears, you probably have a wrong sequence event in your code.