Big thanks to dave123 over at VEF for this guide. http://vintage-erotica-forum.com/showpost...ostcount=437
IHG doesn't recognise WebP as a valid image format and will fail to download them. In order to fix the issue you'll need to add an extra line of code into a file inside the IHG package.
1. Click on the arrow beside the IHG icon.
2. Click Host File Editor.
3. At the bottom of the editor window, you will see a text box where the location of IHG installation is written. It looks something like this >> C:\Users\{username}\AppData\Roaming\Moonchild Productions\Pale Moon\Profiles\fklnk6bu.default\extensions\{E4091D66-127C-11DB-903A-DE80D2EFDFE8}\hostf.xml
4. Copy that whole location address.
5. Remove the last part hostf.xml from the address & paste it in the file explorer address bar. It should open a folder.
6. Go inside more folders.. chrome > content > imagegrabber
7. Locate the file globals.js
8. Right click on that file > edit in any text editor.
9. Looks for the line that starts with this term >> ihg_Globals.LinksByFileExt
10. Add the following highlighted line into there.
ihg_Globals.LinksByFileExt = {
Image: [["Bitmap", "bmp|dib", /^\x42\x4D/],
["GIF", "gif", /^\x47\x49\x46\x38[\x37\x39]\x61/],
["Icon", "ico", /^\x00\x00\x01\x00/],
["JPEG", "jp(?:eg|[eg])", /^\xFF\xD8\xFF/],
["PNG", "png", /^\x89\x50\x4E\x47/],
["WebP", "webp", /^\x52\x49\x46\x46/],
["TIFF", "tiff?", /^(?:\x49\x49\x2A\x00|\x4D\x4D\x00\x2A)/],
["Virtual HD", "vhd", /^\x63\x6F\x6E\x65\x63\x74\x69\x78/]] /*,
11. Save the file.
12. Restart Pale Moon.