Trace Image Doesn't Work

When I try to trace my image, it produces many small triangles.
Please see my screenshot and the image that causes the error.

I cannot upload the image, which is a TIFF file.

Consider converting your TIFFs to PNGs before placing and tracing them.

It has nothing to do with the image format. The plugin had a problem in newer versions of macOS. I had fixed that for the Glyphs 3 version already and now the versions for Glyphs 2 should work, too. To be save to get the new version, remove and reinstall it in the Plugin Manager. Then restart Glyphs and it should work.