Runtime Error: the operation * cannot accept the arguments "empty string", 1

[KONG_SHIEW_CHEE]

I'm trying to code an app for creating the graph based on the textbox-inserted data, but I've faced some problems...

Here's the error message that I received:

I've already tried to find out what's the error but I failed, willing to look for help!

The PNG of my blocks:

And this is the aia file:
GraphDictionary (1).aia (16.3 KB)

I hope someone can help me... Greatly thanks!

[Taifun]

@KONG_SHIEW_CHEE

I've already tried to find out what's the error but I failed

You are trying to multiplicate an empty string with 1. Make sure the textboxes do contain a number before trying to multiplicate

Taifun

[KONG_SHIEW_CHEE]

I tried to use the block without multiple, but my graph showed this

What should I do?

[Taifun]

That multiplication by 1 seems to be necessary as @TIMAI2 explained here

Creating Multiple Line Graph with Textbox Data

You need to ensure that your textbox values are numbers

My suggestion was this

@Taifun

Make sure the textboxes do contain a number before trying to multiplicate

You also could initialize the textboxes with 0 or add an if statement for both textboxes like this

If is empty Textbox.Text
Then set Textbox.Text to 0

Taifun
PS: I'm not familiar with the ChartMakerPlus extension