odd problem with "set opacity"

On my project I thought I would set an opacity to an image to show it's inactive.

I have set up a test .apz to show whats going on.

I have a button which switches the opacity between 100 and 10. Works perfectly.

I have set up a file browse which sets an input and a paragraph to the files location and name.

when it starts the button switches the opacity but once the file search has happened the opacity button gets errors.

No idea where I am going wrong..

Can somebody have a look for me please

Cheers

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