Plugins

[sparky 1987]

Just installed Resynthesizer plugin and trying to understand how it works but the heal transparency does not seem to do whay I have seen in a tutorial.
To start with the eraser does not make a transparent slection on the picture instead it is black unless I add  alpha channel
Then the heal transparence tool does fix but fixes black and leaves the spot I cleared and creats messages about something wrong and also leaves , see file

[rich2005]

That looks like a Gimp 3.0.nn to me not Gimp 2.10, however

Heal Transparency will fill in a "hole" - a transparent area - with the surrounding pixels.

You get that error message when the border of the "hole" contains semi-transparent pixels. If you made the "hole" using the eraser tool then down near the bottom of the eraser tool options is a tick box for "hard edge" - enable that and start again.

The heal selection does what it says, make a selection (with a hard edge) and it copies surrounding pixels into the selection.

This a 60 second animation demo - first heal transparency with semi-transparency - then with "hard edge" - finally a simple heal selection. https://i.imgur.com/wPxMrex.mp4