Balathustrius
We're sorry for the inconvenience. To further look into the problem and help you solve it, we hope you can send us the logs.
You just need to go to SKYBOX's Global Settings, change the Logging Levels to "INFO", reproduce the "File does not exist!" issue, and click the BUG icon in the upper-right corner of Global Settings, and send us a bug report attached with logs(tick the "upload logs" box).
Looking forward to hearing from you.