argument error (Bad arguments to + The operation + cannot accept the arguments: , [asdf], [1])

[Lim Gayoung]

screen1

screen2

screen3

screen4

Hello.

I'm having a problem - when ever I try to click button 4 in Screen 4, an error message appears.

If I write "asdf" in TextBox1 in Screen4, the error message says: 

Bad arguments to +

The operation + cannot accept the arguments: , [asdf], [1]

Please help me. Thank you.

[Evan Patton]

If you're planning to use the content of TextBox1 in a math operation, consider turning on the NumbersOnly option so that the user of the app can only enter valid numbers. If you're intending to concatenate the string "asdf" and the number 1 in order to get the string "asdf1", use the join block in the Text drawer rather than the Math's + block.

Regards,

Evan