how can I upload web icon in wordpress?

I tryed to upload image as website icon, but it always ends unsuccesfully due to error during cropping the image I tried to upload it threw appearencee but it always ends up in error (exchanged format, uploaded another image etc. . Anyone any idea how to fix itor hhow to upload it differently?

Thank you

enter image description here

enter image description here

during upload of image it shows error message: error during cropping the image. after its unable to save it or do anything with it