Every 3 years or so, updates to your templates are needed to prevent compatibility issues and odd behavior. (See more on SOLIDWORKS 2020: https://www.gsc-3d.com/3d-design-soft...)
Learn how to update your template versions in this tutorial.
Details and steps of this video include addressing:
the architecture, foundation, or base programming of your templates
right-clicking a template and selecting "properties" to see their year
locating where your templates are stored
calling up new templates to a new folder after deleting old templates
whatever SOLIDWORKS' version you're on, the system will create templates in that year
Need support as a GSC customer? Visit https://www.gsc-3d.com/support/