One cause of the Error -43 message is trying to run Screenwriter 6.0 on MacOS 10.13.x High Sierra. Screenwriter 6.0 is not compatible with High Sierra. The proper solution is to upgrade to Mac Screenwriter 6.5, which is High Sierra compatible.
If, however, you are running Screenwriter 6.5 and the message says there is no default template, you have two ways to fix it. One way is to reinstall the software, which should reinstall the templates as well.
The alternative is to create a new default template by doing the following:
- Open a document that has the format you want as your default. If you do not have one, open the sample screenplay document -- or any of the sample documents that have the format you'd like.
- Use the Format>Element Styles menu command.
- Check the Save as Default for all new Documents checkbox located in the lower right corner of the Element Styles window.
- Click OK to save the changes and create the default template.
RESTATING: although you can "fix" this issue, there are other incompatibilities with MacOS 10.13 High Sierra that necessitate upgrading to Screenwriter 6.5.
Related Article: Upgrading to Mac Screenwriter 6.5 from Screenwriter 6