I have TW 5.2.7 on Tiddlyhost. This tiddler uses Wiki text. This is an example of one link that did not get linkified because of the characters “[” and “]”.
TiddlyWiki has several ways to create external links (i.e., links to other sites, not links to tiddlers).
Any text separated by whitespace that starts with certain “protocol” sequences such as “http://”, “https://” is handled by the “extlink” wikirule. The following protocols (defined in $:/core/modules/parsers/wikiparser/rules/extlink.js) are recognized by the TWCore: file|http|https|mailto|ftp|irc|news|data|skype.
Alternatively, you can use the [ext[...]] wikitext syntax to enclose any external link, even if it uses a protocol that is not one of those shown above. However, because this syntax uses square brackets as delimiters, you can’t specify a URL that contains square brackets, which is the problem you encountered.
One way around this is to “URL encode” the square brackets, using %5B for [ and %5D for ]. Of course, this is a bit of a nuisance, since you have to hand-edit the URL to change the square brackets to URL encoded sequences.
Fortunately, there is an easier way to deal with the offending URL, by using HTML <a href=...> (anchor) syntax, like this:
Note the addition of target="_blank". This makes the link open in a new browser tab, so that clicking the link won’t cause the current tab to exit your loaded TiddlyWiki.