(In reply to comment #0)

Two things that should be fixed before the switch-over to the Vector:

"wikieditor-toolbar-help-content-heading1-*" is not needed or at least there

should be a note that it shouldn't be used in articles "(nie powinien być
używany w artykułach)"

in "wikieditor-toolbar-help-content-signaturetimestamp-result" and

"wikieditor-toolbar-help-content-signature-result" please replace
"\x3etalk\x3c" with "\x3edyskusja\x3c" or remove it (along with the link around
it) - AFAIK, by default, the talk page link is not available.

The latter seems to be a translation issue (English vs. Polish) and should be fixed on TranslateWiki, the former is about a wiki-specific policy and can be fixed by overriding the message in the MediaWiki: namespace.

Neither require changing the actual software, resolving as INVALID.