Copy-paste fix pattern
fn main() {
string typed = input("Amount")
u256 amount = parse_u256_or(typed, zero)
save amount
}Why it happens
Text could not be parsed into the requested numeric type.
How to fix it
Check for empty strings, unsupported characters, decimal format errors, or missing fallback values.
Runtime and Studio now show this kind of page from the error dialog: plain message first, stable code second, original details third.