As I've mentioned, there are some other incorrectly encoded translations. You need to unpack the language jar-file, find the file with the i18n-key you need to update and replace the translations with the correct ones.

There is a guide who to repack the bundled libraries:

https://confluence.atlassian.com/confkb/how-to-edit-files-in-confluence-jar-files-103711179.html

Dmitriy, we need yours help again. Yours solution working only for "screensot-1.png". "screensot-2.png" and "screensot-3.png" still have problems.

Thank you guys for the providing the workaround solution!

Andrey, I've attached my file (confluence-language-pack-ru_RU-6.6.0.m28-v2r93416-2017-11-28.jar), it is for confluence 6.6.0.

I am not sure, if it'll work correctly for other confluence versions. If it's your version, you can replace the same file in subdirectory confluence/WEB-INF/atlassian-bundled-plugins in the application directory (I've also replaced the same file in confluence/WEB-INF/atlassian-bundled-plugins-setup directory but I'm not sure that it is necessary).

If you want to modify your file, you should unpack jar and edit the i18n-key I have mentioned above in this file:

com/atlassian/confluence/plugins/metadata/jira/i18n_ru_RU.properties 

As I've noticed, the following problem is not the only incorrectly encoded translation, there are many of them on other pages/menu/etc

Dmitriy, add fixed jar to thise issue, please.
And write full path, where we need to change thise jar.
Thank you!

I have found the exact unicode-escaped sequence in language JAR (confluence-language-pack-ru_RU-6.6.0.m28-v2r93416-2017-11-28.zip in my case) for this i18n-key:

content.metadata.jira.items=\u00D0\u00A1\u00D1\u0081\u00D1\u008B\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA JIRA\:{0} 

>>> print u'\u00D0\u00A1\u00D1\u0081\u00D1\u008B\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA'
С��лок

I've changed this line, repacked the JAR, replaced it in atlassian-bundled-plugins and atlassian-bundled-plugins-setup, restarted the application, and it worked!

PS Don't forget to Ctrl+F5 the page if you don't see the changes.

Hi!
it is also related for the 6.6.3

I have tried to set parameters in this time it is not supported.

Could you update the Jira issue, (I mean the affected version field)?

Cheers,
Gonchik Tsymzhitov

And after used paramert:

CATALINA_OPTS="-Dsun.jnu.encoding=UTF-8 -Dfile.encoding=UTF-8 -Dencoding=UTF-8 ${CATALINA_OPTS}"

We still have problem in 6.6.0 with encoding.
(Screen-2 and 3)

We too  6.6.0

We are having the same issue in Confluence 6.6.0 with Russian translation