So it looks like the issue was because of the two IE specific MIME types (pjpeg & x-png)… I seem to have figured out an interim solution to the issue:
Open frontend-uploader.php
Add this code after line 115
$ie_mimes = array( 'image/pjpeg','image/x-png');
Update line 118 from:
if ( in_array( $k['type'], $this->allowed_mime_types ) ) {
to this:
if ( in_array( $k['type'], $this->allowed_mime_types ) || in_array( $k['type'], $ie_mimes) ) {
Hope that helps!