Blending Option Goes Crazy

I typed a word then I went to "Blending Options"
I changed "Knockout" to "Swallow" then the "Opacity" to "0".
Powwww the magic . the program crashed and closed itself.
Moreover it does that everytime I repeat the process.
So, I am stuck here and I cannot move on and do my job.
There is no way to write a transparent text.
I hope yout find a solution as soon as possible; otherwise we will have to go back to old photoshop versions.