Parallel lines in place of image

Using the standalone builder v. 2020.1.3 (Windows 10), I cannot get .bmp or .jpeg images to display.

Images are to be called from a csv pointing to the file location [Locations and extensions have been double checked. Some images were converted to jpeg and the csv was modified to attempt to isolate the problem.] and displayed for three seconds. Rather than displaying the image, two vertical, parallel white lines are shown for the duration. These lines are presumably where the outer edges of the picture should be. I can modify the relative height and width of the “image” and the parallel lines change accordingly, but no image appears.

I have tried jpeg conversion, changing the units (norm, pix, height) for both the experiment and the imagestim setup. Using “sin” in the image setup GUI seems to allow the program to step through the csv, but changing that to “$stimFile” in the GUI and “stimFile” in the csv column header results in a different error. (NameError: name ‘stimFile’ is not defined)

Any help would be much appreciated.