For newbies, I recommend to translate it. You can use Translation editor plugin also.

Thanks RvR! I was able to modify the menu name to "Calendar" and modified the Plugin name to "Event Calendar" (first letters capitalized).

It means you're using the deprecated function expose_function() (perhaps, in 3rd party plugins).

You should replace this deprecated function on elgg_ws_expose_function().

Read this Article: https://www.shoutmeloud.com/domain-authority.html

Following is a list of ranking factors (with explanations) which will have maximum impact on your DA and PA (page authority):

Days to expiry of domain name:

This is probably the easiest thing you can do right now to affect your domain ranking. Days to expiry is not a terribly strong factor, but it is a deciding factor in the establishment of a good website. It indicates to search engines that these long-lasting websites can be trusted. If your domain is set to expire in the next year, I would recommend that you extend it for the next 3-4 years. It would cost a just few dollars more, and it would be helpful to you in the long run.

Get more links to your site:

This is probably the one factor which will affect your DA score the most. Try to earn as many backlinks as you can, but make sure those links are from quality sites. If you buy backlinks or get links from low-quality sites (using automated methods), you will do more harm than good. (See: Google Penguin & negative SEO)

Diversify your link profile:

Instead of getting tons of links from a few sites, focus on getting quality links from diverse sources. This would include links from various geo-locations, various domain extensions, and sources which are not interconnected. Needless to say, links should be relevant and should be of high-quality.

Internal link structure:

This is one important factor that you can easily control. Have you visited a Wikipedia page recently? Have you noticed how powerful their internal linking is? Make sure your every post is linked to 2-3 others posts on your blog, and when you publish a new blog post, go back and link from your old posts. This will also pass link juice from old posts to the new one.

Remove bad links:

Along with creating new links, you should also keep an eye out for bad links pointing to your site. You can use a service to monitor backlinks to get email notifications. Whenever a bad link is pointing to your site, ensure that you get it removed, or use Google Disavow tool to ignore those links.

Must read: How the LinkPatrol plugin fixed my external bad links issue

Become an authoritative source in your niche:

The quality of your articles is more important than the quantity of articles. Publishing only 2-3 high-quality posts in a week is far better than publishing 7 posts of mediocre or low-quality content.

Along with publishing high-quality content, work to become an authoritative site in your niche. Become the news breaker or make sure your reader trusts every page on your website.  This will have a great impact on overall user-experience and on your search engine ranking. I’m not entirely sure it is directly related to increased domain authority, but it will definitely advance your site’s search engine ranking.

Note: Domain Authority uses 40+ signals and looks at the pattern of search engine rankings by Google. So if you make Google happy, your DA score will also improve over time.

On-Site SEO :

Make sure your website is search engine optimized, as this controls things like where the link juice passes, how easy it is for search engine bots to crawl your site, and how user-centric your content and navigation are.

Here are few things which you should focus on with On-Site SEO:

Noindex archive pages (Noindex your tags, categories, pagination and author archive pages)
Sitemap file (Have a sitemap file link in your footer and in your robots.txt file). Make sure you have submitted your sitemap file to major search engines like Google and Bing.
Meta title and Meta description of homepage
Maintain proper heading hierarchy in your blog post. Here is a good guide on how to use heading tags for SEO.

Make your website load faster

I could have included page load time in the on-page SEO reference, but I believe since  Google has made page load time an official ranking factor, you should start giving great attention to the load time of your website. You can use sites like tools.pingdom (More sites here) to check the existing load time of your site. If your site is not loading within 3 seconds, you should start working on speed optimization of your site.

Social Media marketing and branding: 

Social media plays a major role in the ranking of your content. Whether social media is a ranking factor for domain authority or not is debatable, but it is definitely a ranking factor in the Google search engine ranking algorithm. Make sure your brand and your blogs have a presence in all major social media platforms. Also try to ensure that your readers are sharing your content on social-media platforms. This helps to boost ranking and improves indexing.

As already posted in the other thread: from the two choices (updating your site from Elgg 1.8 to a newer Elgg version or migrating the Elgg site to Buddypress) I would think that upgrading to a newer Elgg version is much easier!

With a newer version of Elgg you could also try some plugins like https://elgg.org/plugins/2397576 or https://elgg.org/plugins/2626263 for improving SEO.

The most complex upgrade is from Elgg version 1.8 to 1.9 as there are changes in the data directory structure and done and comments entries data model has changed. But that's probably still much easier than trying to migrate from Elgg to Buddypress without very good experience and a lot of time or money (to hire someone doing the job) or both.

Depending on which 3rd party plugins you use on your site the upgrade might be easier (if there a new versions of these plugins for newer Elgg versions available) or a bit more difficult (if the plugins have no newer versions and you can't go without them).

How about thinking seriously about trying to upgrade your site? Maybe try it out with a test installation to learn how it works. Then you can see if the SEO plugins available for the newer Elgg versions improve the ranking. If not, you still could decide to change to wordpress - though I doubt someone would have a ready solution for that and importing/exporting content is not enough.