I can't create a Pattern of a selection area. When I try to create the Pattern at Edit->Define Pattern, this option isn't available.
I will tell you the steps I'm taking:
->Create a new doc and use Paint Bucket Tool to paint it with Black (this is the background).
->Then I create a new layer and with the rectangular marquee tool I do a square.
->Keeping the selection I press cmd+backspace and the square becomes white.
->Keeping the selection I do a Stroke with 2px, color black and option Inside.
->Then I go to Edit to define a pattern of that square, however the Define Pattern option is gray, so I can't use it.
Does someone knows why this is happening?
I can't offer any help because the steps you are providing should make it possible to define a pattern.
If it is a glitch you could try to make Photoshop behave by resetting the Preferences file:
In Photoshop 6 and up, hold down Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac) immediately after (or while) launching Photoshop. A prompt will ask if you want to delete the preferences file. Click Yes.
Thank you! Worked