Could you please check if the profile photo you're uploading meets the guidelines listed here? Please also check if the image you're trying to upload is in .jpg, .jpeg, .gif, .png format and at least 250px by 250px. It is a clear, headshot-style photo of you which is cropped from the top of your head, just below your shoulders, and it meets the following:
Here's a great guide on the perfect profile photo, which I hope helps you choose the best picture for your profile.
If you meet all the guidelines and you're still having issues with the photo you're uploading, please don't hesitate to update this thread so that our team can assist you further.