Inventor is looking in the folder(s) you set up to store external rules. If your rule is not in one of those folders, I would assume you'll get the message you're seeing. To tell Inventor where to look for external rules, go to Tools > Options > iLogic Configuration. There you can specify a folder (or a bunch of different folders) where Inventor looks for iLogic rules, as well as what file extensions and where the iLogic add-in is located.
Hint: image attachments are much smaller in formats other than .bmp; try saving as .png or .jpg.
![Autodesk Design & Make Report](https://forums.autodesk.com/t5/image/serverpage/image-id/1350519iCB55845EBFC43016/image-size/large?v=v2&px=999" "Autodesk Design & Make Report")