I have this error.

awajax.lSuccess(.f.): Error detected at code line #14,267 of method 'awajax.useraction' "FoxInCloud could not process this request: Awajax.useraction() - Error while executing method '_form_bollettino_print.Wformcallback(m.this.uValue)': Method or procedure saveinsent(): error #2031 ("User-interface operation not allowed at this time") at code line #50

What's its meaning ?

Method or procedure saveinsent(): error #2031 ("User-interface operation not allowed at this time") at code line #50

What code do you have at line 50 of saveinsent()?

I guess VFP attempts to open a modal dialog box (eg. messageBox, table open dialog), made impossible by unattended mode Sys(2335, 0) set by FoxinCloud server in production mode.