how to update checkbox or checkbox.setSelected(true)

I dont get an error while coding but I do get an error while running in eclipse java.

I select the data from the table and then update checkbox using checkbox.setSelected(true) and it errors out.

is there any better way in Java to resolve this issue please.

Thanks

I tried saving the selected data into a variable and printed the variable and it shows the right data but while I try to change the status of the checkbox, I get an error.