Blogdown serve_site() no longer working after update

[Datatata]

I recently updated R to version R-4.0.4 and the blogdown package to version 1.1. Upon making this change, I received an error while running serve_site() for my blogdown website.

For reference, my hugo version has been updated to "0.81.0" and my website uses the theme "Hugo W3 Simple". The most recent website commit can be found here on my GitHub profile.

> library(blogdown)
> serve_site()
>
>Launching the server via the command:
  
C:/Users/Cypher/AppData/Roaming/Hugo/0.81.0/hugo.exe server --bind 127.0.0.1 -p 4321 --themesDir themes -t hugo-w3-simple -D -F --navigateToChanged
Error: Error building site: failed to render pages: render of "page" failed: "C:\Users\Cypher\Desktop\ecypher.github.io\themes\hugo-w3-simple\layouts\post\single.html:37:21": execute of template failed: template: post/single.html:37:21: executing "main" at <.>: range can't iterate over hugo

I've referenced the hugo commands and blogdown updates, but I'm at a loss for how to resolve my problem. Any help would be greatly appreciated, and if I need to include more information then please let me know.

[cderv]

I cloned your repository from Github and served the site without error using blogdown 0.81.0 and blogdown 1.1 so I can't reproduce this for now.

You can try using an earlier Hugo version in case your website theme does not support newer version and also check your website using the check_* function.
See the blog post for some information on how all this has improved:

Announcing blogdown v1.0

[Datatata]

I appreciate your input and am happy to report that I found the solution! My single.html file created an issue with some tags included in the YAML headers of several blog posts. I edited the tags, and now everything runs as intended.