Psychopy fails to find image file

Hello,
Please check this error message:
raise IOError(msg % (tex, os.path.abspath(tex)))
OSError: Couldn’t find image stimuli 1/prac_images/a.jpg; check path? (tried: C:\Main Study SPR Test\Test 1\stimuli 1\prac_images\a.jpg)

It also shows this picture:


Although parameters are set

Please advise,
Najat