The free forum platforms like PhpBB, MyBB, SMF aren’t as reliable as Xenforo, Vbulletin among others.
Free forum software and the theme issues
I have downloaded SMF, MyBB, and phpBB. For sure, the default themes don’t look appealing. So, I have decided to look for themes. First of all, I have discovered that many themes were not compatible with my version of SMF and myBB. Then, I have discovered that many themes were incomplete. I have witnessed issues with phpBB, myBB and SMF themes such as links that didn’t work, text fields that opened partially, toolbars of edit page that didn’t show.
I have bought a theme called flatOne for myBB, and I discovered that the login link and the search link didn’t work. However, it was a premium theme, and I paid $30 for it. Then, I have discovered it was very difficult to modify a theme in myBB. I wanted to buy a theme to use it on several websites. I have bought several premium themes for myBB and none of the themes suited my needs.

On the other hand, the themes of Vbulletin and Xenforo look professional, and they are reliable out of the box. Nothing is broken.
On one forum, I have discovered that theme authors didn’t use to maintain their themes. I have found a thread of someone complaining that a theme footer was broken for several years!
In the end, the amount of money that I have to spend in buying premium themes for free internet
Free themes from free forum softwares aren’t responsive
I have found that the default themes of myBB and SMF were not responsive on smartphones. Then, I had discovered that many free themes that were advertised as being “responsive” were barely responsive as they looked messy when I visited the forum from a smartphone. Items were not aligned. Titles were not at the right location. By the way, if you test a forum, don’t use a mobile phone simulation, use a smartphone to see how it looks like.
By the way, if you test a forum, don’t use a mobile phone simulation, use a smartphone to see how it looks like.
On the other hand, all the paid internet forum platforms are perfectly displayed on mobile phones and tablets.
Free Internet forum software and SEO:
On the developers’ forums from SMF, MyBB, and phpBB no one is interested in implementing friendly URLs into their internet forum software. So, they want to keep URLs looking like: /viewforum.php?f=2&sid=6793ae5b47125325d08772c73d628200 which is a URL from a phpBB 3.21 installation
If you want a friendly URL for your free internet forum, you have to find and download a plugin. It is at your own risk because the plugin may not work with the version of your internet forum software.
Also, the free internet forum platforms don’t have a canonical tag by default.
On the other hand, friendly URLs are default features of Xenforo, Vbulletin, Woltlab, and other paid internet forums.
Conclusion:
If you can afford it, It is advised to buy a serious forum platform like Xenforo, Vbulletin because you will save time building up your forum and its template. Also, you will get a reliable solution, and you will not need to install any plugins.
Compared to paid internet forum platform, the webmaster of a free internet forum platform must install and maintain many plugins (SEO, security. features).
I must admit that since free internet forum platforms had a very good reputation online, I didn’t expect that there was so much workload related to installing a free internet forum platform.
The installations of a free internet forum platform are fragile. They can break because of a plugin, a new version of PHP or modification of the template. For example, I saw a PHP error on every single page of a phpBB installation after installing PHP 7.2 on my web server which resulted in messy snippets in Google search results (see picture below).
There is a big reliability gap between paid internet forum platforms and free internet forum platforms.
