https://ru.wikiquote.org/wiki/Special:Redirect/logid/222600
2000::/3 is blocked on ru.wikiquote.
If the contents of https://www.mediawiki.org/wiki/Help:Range_blocks/IPv6#Range_table are correct, this block is affecting 42,535,295,865,117,307,932,921,825,928,921,026,432 addresses (42 undecillion ++); which I suspect it means no one over IPv6 will be able to edit, unless the block is not applying "in the background" (I mean: the log entry somewhat got created but the block is not really being applied despite appearing too in Special:BlockList).
https://www.mediawiki.org/wiki/Manual:$wgBlockCIDRLimit prevents IPv6 rangeblocks greater than /19 to be applied, so I'm not sure how this is even possible.
Edit: Considering that the issue reported might be a leftover of a previous (now fixed) issue; I'm converting to ask if we could have a list of such blocks currently in force so they can be reviewed or removed.