Just press Retry. The image actually exists so no idea why it does that to be honest :/
Hi NickSav
You said the image already exists but that isn't completely accurate. In the project there is an img_CGC/bases/Default.png_ This is the encrypted version of the Default.png file. From what I can see there are 2 possible solutions. Include the Default.png unencrypted or find the code that is calling the unencrypted file and convert it to using the encrypted file.
On my own I found a reference to the unencrypted file in the MYTH_CGC_CoreEngine.js file. So I'm not sure how feasible it would be to convert this to using encrypted files. Also I don't know if there are any other references to the unencrypted file.