Lock specific cells

I created a program that requires an input to the user in the specific cells and if he clicked the button (VB codes), it will print the output in the other cells.
I successfully locked the non-input cells (so that the users will only put numbers in the input cells) but when I clicked the button, there's an error. It looks like it qualifies it as an edit in the locked cells.

If you know how to solve this or know other methods to lock the non-input cells, it would be a help. I only want the users to avoid encoding characters in the non-input cells. Thanks.

Select cell>right click> Format cell> Protection> click locked