I tried uploading a template and received the following error: Error packaging document: Error: Unable to place snippet files. Please rebuild your file.

- Please be sure that you are using the latest version of the PrintUI Management panel. 

- Check the size of the zip file, if it is larger than our maximum file size for uploading which is about 800 to 900 MB (total package), that could be an issue. I'd start by reducing the file size of some of the images.

- Another possibility is that the original document has become corrupted.  This happens from time to time, especially if you open a document created in an older version of InDesign.  One way to remove the corruption is to package the document and then open the IDML file instead of using the original.

- It could be that you have multi-page spreads (two pages connected as one), which we don't support. To do that go to File > Document Setup and uncheck Facing Pages and In the ID Pages panel make sure the "Allow pages to shuffle" is checked..

- You should also check the Troubleshooting section of the Tips for Designing Templates for PrintUI available at https://printui.zendesk.com/hc/en-us/articles/115001055674-Tips-for-template-designers