Server Error : Logo on Welcome Page

During upload of logo picture on Welcome Page , 'server error' message appears. 

I have cloned your form and was able to upload an image without a problem.

Make sure the file you are uploading is JPG or PNG. Also, try using another browser and see if that helps.

If you are still having issues, please take a screenshot of the browser's console and send it here.
How to get a console report from most common browsers?