If the file is around 2 mb or more I have to use Imagemagick to be able to see thumbnails for the images when I upload them as attachments. I have attached two images to this post where you see the difference with uploading a 2 mb file with both Imagemagick and PHP GD.
It's strange though that I'm not able to upload a profile image with Imagemagick turned on? I have tried different images and none of them work.
Ok. First I try Imagemagick with a image that is 80 kb large. I got this message:
Fatal error: Maximum execution time of 30 seconds exceeded in /home/biirds/public_html/library/XenForo/Image/ImageMagick/Pecl.php on line 261 I then made the image smaller but got a message that the image was larger than 50 kb and couldn't be uploaded.
I switched to PHP GD and then I could upload the image with no problem.
It sounds like an imagemagick issue, where it's just taking it a long time (or spinning). The line where it's dying is where it processes the image. You may wish to try a newer version of the PECL extension (or compile it against a newer version of IM).
My host did increase the max execution time value in php.ini and now it works to upload a avatar with Imagemagick. It takes very long time for the image to be uploaded though =/, but I will hear with them if there's something you can do to increase the uploading time.