GIMP bug or system fault?

[Gerrit T]

What is happening here?

[rich2005]

You need to give a lot more information than that image. A screenshot of the whole Gimp interface showing tools and layers docks as a minimum but also version of Gimp, properties of the image you are editing - file format and precision + what you were doing when that happened, using a plugin for example.

[Ofnuts]

It could also be a corrupt image. Is the file size coherent with other pictures oif the same series? If yes, if you ZIP the file, is the a marked difference in size (a good JPEG is hardly compressible, so if the file gets smaller its is probably because it contains null bytes).