Hi Arlex,

Thank you, that's it. Unfortunately our blog is not only in English. Do you know if there is any consequences of using these characters in URL's?

Regards,
Mark

From what I research, it seems like there will not cause any other issue if the URL contain those symbol like comma because the comma ( " , " ) reserved character is often used for similar purposes, you can read more what others reserved character here .

Even the URL contain "*" other browser also considered it as the valid URL, for example :

[gist type="php"]
http://web.archive.org/web/*/http://www.example.com/
[/gist]

If you really want to get rid of those comma symbol in URL, then you have to modify on this core file
JoomlaFolder/administrator/components/com_easyblog/includes/router.php

You can take a look my attached screenshot below.

[gist type="php"]
// Remove comma or other symbol as well
$excludeSymbols = array(',');
$permalink = str_replace($excludeSymbols, '', $permalink);
[/gist]