- Flush cache and re-indexDo not forget that images upload is the bulk procedure and in order to be able to see the changes at the front-end, you need to do the mentioned actions.
- Magento image sizeMagento images size should be less than 2 MB (since in most cases Magento does not upload bigger images).
- Spaces in image namesCheck if in image names there are no spaces, as sometimes spaces can be treated as additional symbols and because of this Magento images may not be shown correctly.
- Images sort orderOften small image/thumbnail image may not display when multiple images are loaded. In this case, it may help to set sort order of the image that should be shown as small / thumbnail to 0 or 1.
- All image types checkboxes checked and columns assignedMake sure that during Magento import products images procedure, you assign images to media gallery and that they are assigned as small, base and thumbnail. In case you do it manually, check all the radio buttons.
- Image from the URLMake sure that your Magento import products images method handles upload of the images from external sources. In case you are using default Magento import method, it does not support remote images. You need to download Magento images and locale them to your FTP before the process.
- Correct subfoldersCheck if your images were uploaded to correct subfolders at your FTP. For Magento import images process you need only image name in the file indicated. Then they should be uploaded to media/import folder. After Magento import products images procedure, the images will be placed to corresponding sub-directories created on the basis of image name, for example - the image name is “image123.jpg” and after import it will be placed to sub-folder i/m/image123.jpg (first sub-folder corresponds to 1st letter and second folder created on the basis of 2nd letter of image name). Check if your images physically uploaded to FTP and exist there.
- “Image does not exist”This error actually means that image was not uploaded correctly or was not uploaded at all. The first thing you should check is if the image file is actually in the subfolder where Magento expects it to be. Once checked, try any other method for uploading Magento images. In case you’re uploading it with Admin, try another browser and make sure that pop-up blocker is turned off there. Once one image is loaded correctly, all other images will go smoothly as well.
- Media folder permissionsCheck if your media folder has all the permissions that allow you to do all the changes. In case there are some restrictions, most likely you won’t be able to upload images. There can also be some issues with the owner of the media folder - it occurs when you move Magento from another server. Check it out with your hosting.
- FTP quotaCheck if there is enough space at your FTP for images upload. If you exceed the quota, you will need to delete some of images that you may not use anymore to ensure enough space for successful Magento import images of new items or you can enlarge the quota with your hosting company.
If all the above points are checked, but if the issue still remains, you can try to upload images or perform Magento import images procedure via the application called Store Manager for Magento. It handles both good import of local and remote images and automatically uploads them to your FTP to appropriate directories. Also there is very convenient built-in Store Diagnostics tool that allows you to see missing product images or those which are not linked to products. In case you have great number of products, it will save your time considerably, as you will always be aware of the state of your product images.
Do not let yourself to get caught in an endless loop of Magento images upload issues. Find easy way to communicate with your clients and build up proper owner-to-consumer business relationships. Adding images via Store Manager for Magento will not only help attract more buyers, it will improve the overall level of attractiveness of your online business.
Source - http://www.mag-manager.com/useful-articles/tipstricks/what-to-check-if-you-cannot-upload-magento-images