.pdn file is not supported at imgur. Open with paint.net and export the image to .jpg or .png, then upload it to imgur. Or you can use another image instead.
It's not that hard. Take a screenshot with f2. Go on forums and click upload file. Type in %appdata%, click on .minecraft then on screenshots. Click the folder and upload it EDIT: If its not a picture on minecraft download lightshot https://chrome.google.com/webstore/...t-tool/mbniclmhobmnbdlbpiphghaielnnpgdp?hl=en Take a picture and upload it the same way, just remember where you exported the picture
There is a limit for the file size. You can't use that when you add images in your signature. It takes some time when other users try to zoom in your images. You can edit your images easily with imgur.
I have a simple signature if I need it -JohnBean2014 signature here btw '(' EDIT: You can click Full Image and they don't have to zoom in and imgur isnt very mobile friendly