@Moose could you send us the output from /Applications/Utilities/Console.app to us via firstname.lastname@example.org (it contains information you may not want to disclose on a public support thread, hence requesting via that route), please? It sounds like the issue could be with certain cache data that the application prepares regarding the templates and citation styles having gone into a bad state. I have a possible idea for workarounds in case that is the cause:
Does clearing the settings and cache directory created by Manuscripts application help? To clear Manuscripts into its "factory settings", please complete the following steps:
- Open Finder.
- Go > Go To Folder (or hit Shift+Command+G)
- Enter ~/Library/Containers into the window that opened and then click "Go"
Once you've done that your Finder window should be now in a folder where you see the folder "com.manuscripts.Manuscripts".
Please drag the folder com.manuscripts.Manuscripts into Trash (this clears the cache directory that contains safely deletable information that improves the performance of Manuscripts and which it uses when exporting documents, etc).
Copy and paste the following into the terminal window, and hit Enter after:
defaults delete com.manuscripts.Manuscripts
CEO & Co-founder of Manuscripts.app Ltd