Hello, I need help to solve a problem in mit app inventor, when I try to test the application that I made, a warning appears as shown
in the picture. on the left is the code I compiled
in the picture. on the left is the code I compiled
as the error message is telling you, there must be arguments available for a subtraction, for example 3 - 1 = 2
in your case the first argument is an empty string...
before doing a subtraction make sure, both arguments are numbers
Taifun
sorry before that I don't know which part is an empty string, may I ask for your help to mark which part is an empty string. do i need to attach the file?
Looks like length of Label8, the only place in your blocks where you are subtracting
the error does not occur in the blocks from the screenshot, because you are subtracting 5 there...
you have to check your blocks and find the blocks where you are subtracting 1
If you are asking for help, I recommend you to make it as easy for others to be able to help you ...
You probably will get more feedback then...
which means in your case post a screenshot of your relevant blocks...
To download the aia file, upload it to App Inventor, open it, do some bug hunting for you, etc... this takes time, and most people will not do that...
Thank you.
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
why don't you search the blocks yourself?
for example
which means, make sure to set Textbox1.Text to 0 before doing a subtraction or use an if statement like this
if is empty Textbox1.Text
then display a notifier "Sorry, I'm not able to subtract"
else do the subtraction
Taifun