Inadequate format and/or size of the photo. You can easily upload images in the following formats: jpeg, png. The applied size limits are: not smaller than 1080 pixels and not larger than 10 MB.
Weak or no internet connection.
If you are using the website, your Internet browser may not be functioning correctly. Make sure you are using the latest version of your browser, or try using a different one.
Camera or gallery applications not having permission to upload photos to the site. If you are using an Android device, you can authorize the applications by going to settings, choosing "applications" from the menu, selecting the browser you are using, and clicking on "permissions" to authorize the camera and memory. If you are using an iPhone, you can authorize the applications by clicking on settings, finding the browser you are using, and granting it access to the camera and gallery.