Cannot build on latest hugo about hugo-universal-theme

[ryanfox1985]

it works fine in my end:

version: hugo v0.121.2+extended linux/amd64

> hugo server
Watching for changes in /home/guillermo/workspace/hugo-universal-theme/{archetypes,exampleSite,i18n,layouts,package.json,static}
Watching for config changes in /home/guillermo/workspace/hugo-universal-theme/exampleSite/config.toml
Start building sites … 
hugo v0.121.2+extended linux/amd64 BuildDate=unknown


                   | EN   
-------------------+------
  Pages            |  43  
  Paginator pages  |   0  
  Non-page files   |   0  
  Static files     | 105  
  Processed images |   0  
  Aliases          |  17  
  Sitemaps         |   1  
  Cleaned          |   0  

Built in 70 ms
Environment: "development"
Serving pages from memory
Running in Fast Render Mode. For full rebuilds on change: hugo server --disableFastRender
Web Server is available at http://localhost:1313/hugo-universal-theme/ (bind address 127.0.0.1) 
Press Ctrl+C to stop

[al3xandru]

This is with a clean clone:

WARN  calling IsSet with unsupported type "invalid" (<nil>) will always return false.
ERROR render of "page" failed: "~/themes/universal/layouts/_default/single.html:35:65": execute of template failed: template: _default/single.html:35:65: executing "_default/single.html" at <.Site.Params.date_format>: invalid value; expected string
ERROR render of "section" failed: "~/themes/universal/layouts/_default/list.html:59:75": execute of template failed: template: _default/list.html:59:75: executing "_default/list.html" at <.Site.Params.date_format>: invalid value; expected string
ERROR render: failed to render pages: render of "page" failed: "~/themes/universal/layouts/_default/single.html:35:65": execute of template failed: template: _default/single.html:35:65: executing "_default/single.html" at <.Site.Params.date_format>: invalid value; expected string
Rebuilt in 51 ms

[ryanfox1985]

still not reproduccing the error: