Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.
If that does not resolve the issue, try switching to the default theme for your version of WordPress to rule-out a theme-specific issue (theme functions can interfere like plugins).
Also try going to the Dashboard > Updates section in your dashboard and make sure that you are on the most recent version of WordPress. If you are then maybe hit the re-install button to let it re-install the most recent version of WordPress to rule out possible damaged files.
You can also use an open-source alternative like Paint.net or GIMP to edit your photos before you upload them. I like to crop my images in Paint.net and compress them, losslessly, in JPEGmini (this program costs ~$20).
