when you use for the variable j already contains the item in the array - you are trying to use j as an index to the array!
here’s what you get for the first iterations of for and , based on your usage, the corresponding item in the same array!
iter1 , j=8, 8th parameter of Problist → 2
iter2 , j=4, 4th parameter of Problist → 5
iter3 , j=7, 7 th parameter of Problist → 7
iter4 , j=4, 4 th parameter of Problist → 5
etc.
that;s why your output is 2,5,7,5,…
just change your set statement to use j directly
set "Error txt"s text to “j”
Sorry sorry so silly of me. You are right, thank you very much. The documentation is also right. I wish Thunkable would give bit more detailed information with a working simple example. Thanks again