You may have recently purchased Auto Apply, or you have had it running for a while and notice some of your items without your template applied.
There could be many reasons for why your template hasn't applied, you can find this reason inside of the eBay Design Auto Apply page within Frooition.

Simply click on the eBay tab (inside of Frooition) > Auto Apply Design

You will be taken to the following page:

On the above page, you can see examples of items that have applied correctly, and one example that has not. Within the table, you get a detailed description of the reason why your item cannot be revised due to certain eBay errors.
In the above instance, you will see a UPC is missing. In order to fix this, we would advise relisting the item with a UPC. (or relist fixing the issue as stated) This will then allow the item to be Auto Applied.

If you wish, you could revise the item on eBay, but to add your custom template, you would need to use Bulk Revision as shown here: