Redmine

Probably related with Defect #22967

URI lib replacement can be also a solution https://stackoverflow.com/questions/30923469/ruby-uri-escape-and-uri-encode-and-uri-parse-error

https://github.com/sporkmonger/addressable

One more example of broken link: [Letters](https://yandex.ru/search/?text=кол-во) - so any no latin letter broke link.

URIs are defined in RFC 3986 to be allowed to only contain a defined subset of ASCII characters. All other characters must be encoded.

Browsers often perform this automatically. Thus, when you enter the checkmark character in your browser's address bar, it encodes the character to %E2%9C%93 before it is sent to the server. This is the canonical URI representation. Redmine now needs to ensure at various places that some URIs are valid. It does this by attempting to parse the URI according to the rules of RFC 3986. In the case of "special" or cyrillic characters, this fails since these characters are not allowed in a valid URI verbatim.

As a workaround, you need to ensure that URIs are properly encoded when entering them in Redmine. Many browsers, including Chrome and Firefox automatically copy an encoded URL to your clipboard when copying a URL from the address bar which you can use for this purpose.