Hi, Neil.
Thank you for reaching out! Let me ask if you a few questions to narrow down the issue:
- Your error message shows that the folder you are trying to save the file to is called DROPBOX. Is this just a name, or is this folder one that syncs with Dropbox? If so, is smart sync turned on?
- I am not very familiar with Dropbox, but I'm guessing the smart sync could have the same issues as working on a network drive. We recommend working from a local hard drive.
- Have you attempted to repair Storyline 360? Here are the instructions.
Let me know if those help you!