Page Build Error while building a site with Jekyll

I'm building a site portfolio using Jekyll. Currently I'm referencing DataOptimal through they GitHub page and YouTube channel.

I've customised my site but when pushing changes into Git, I encountered a Page Build Error message as follows:

The page build failed for the master branch with the following error: A file was included in _pages/project.md that is a symlink or does not exist in your _includes directory. For more information, see https://docs.github.com/github/working-with-github-pages/troubleshooting-jekyll-build-errors-for-github-pages-sites#file-is-a-symlink.

I have accessed the link, and probably the most relevant suggestion based on the above error message is this:

File is a symlink. This error means that your code references a symlinked file that does not exist in the publishing source for your site. To troubleshoot, search the file in the error message for include to see where you've referenced other files, such as {% include example_header.html %}. If any of the files you've referenced are symlinked, copy or move the files into the _includes directory.

So looking at my code under _pages/project.md:

{% include base_path %}
{% include group-by-array collection=site.posts field="tags" %}
{% for tag in group_names %}
    {% assign posts = group_items[forloop.index0] %}
    <h2 id="{{ tag | slugify }}" class="archive__subtitle">{{ tag }}</h2>
    {% for post in posts %}
        {% include archive-single.html %}
    {% endfor %}
{% endfor %}

I presume that the error is coming from archive-single.html so I went into _includes directory to check if the file is in, and it is in, so it exists.

So it turns out that maybe archive-single.html was not the issue. I can't seem to pinpoint where is the error to rectify it. Am I interpreting symlink wrongly?

Appreciate any inputs to assist on this.