List index too large?

Hello! Im currently working on a sudoku app and every time I try to run it it tells me that my list index is too large. How do I fix this??

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Thank you in advance!!

Rough guess, it is in here:
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where you first load a list from global random textboxes (it is not evident how this is generated), then you test to see if it is empty ?

but you will need to do some bug hunting to track down which list in which set of blocks is causing the problem

Your app is harder to debug because its variables and procedures are not named informatively.

Examples:

procedure procedure could be named NN to show it returns 2 digits.

List list is a total wild card. Who knows what it is a list of?

Naming things properly is important.