It seems like all that has happened is that - has replaced +, as when a user joins/leaves, - is displayed regardless.

I've been experiencing those errors with article feedback as well, but I didn't report them as I didn't see "database error" and as such didn't report it.

I just received a different database error while using Special:Search, which included the backtrace log below. I was searching for the term "Butterfly sword", just in case that matters (probably not).

#0 /var/www/core/includes/db/Database.php(1076): DatabaseBase->reportQueryError('Out of memory (...', 5, 'SHOW GLOBAL VAR...', 'SearchMySQL::mi...', false)
#1 /var/www/core/includes/search/SearchMySQL.php(442): DatabaseBase->query('SHOW GLOBAL VAR...', 'SearchMySQL::mi...')
#2 /var/www/core/includes/search/SearchMySQL.php(397): SearchMySQL->minSearchLength()
#3 /var/www/core/includes/search/SearchMySQL.php(104): SearchMySQL->normalizeText('Butterfly')
#4 /var/www/core/includes/search/SearchMySQL.php(294): SearchMySQL->parseQuery('Butterfly sword', false)
#5 /var/www/core/includes/search/SearchMySQL.php(268): SearchMySQL->queryMain(Array, 'Butterfly sword', false)
#6 /var/www/core/includes/search/SearchMySQL.php(183): SearchMySQL->getQuery('Butterfly sword', false)
#7 /var/www/core/includes/search/SearchMySQL.php(173): SearchMySQL->searchInternal('Butterfly sword', false)
#8 /var/www/core/includes/specials/SpecialSearch.php(264): SearchMySQL->searchTitle('Butterfly sword')
#9 /var/www/core/includes/specials/SpecialSearch.php(209): SpecialSearch->showResults('Butterfly sword')
#10 /var/www/core/includes/specials/SpecialSearch.php(125): SpecialSearch->goResult('Butterfly sword')
#11 /var/www/core/includes/specialpage/SpecialPage.php(384): SpecialSearch->execute(NULL)
#12 /var/www/core/includes/specialpage/SpecialPageFactory.php(553): SpecialPage->run(NULL)
#13 /var/www/core/includes/MediaWiki.php(281): SpecialPageFactory::executePath(Object(Title), Object(RequestContext))
#14 /var/www/core/includes/MediaWiki.php(714): MediaWiki->performRequest()
#15 /var/www/core/includes/MediaWiki.php(508): MediaWiki->main()
#16 /var/www/core/index.php(41): MediaWiki->run()
#17 {main}

These database errors aren't limited to editing pages only. I've been experiencing a myriad of errors related to this. Like Nova said, the search bar will sometimes give a database error that prevents it from working (it must be refreshed several times until it actually does work), and previewing a page that is affected by the database error from the source editor may or may not give an error sometimes. Simply attempting to access some pages that haven't been edited will also give the error (but can be read in source mode as wikitext).

I'm not sure if this would be classified as the same error, but I received a similar "database error" on another page.

In T144249#2594783, @ashley wrote:

The Poll namespace and associated special pages (Special:CreatePoll, Special:ViewPoll, Special:UpdatePoll, Special:AdminPoll and Special:AdminPoll) seem to have never been used on ENBP. Perhaps disabling those special pages/namespace(s) would be better.

Yes, what you've found is a bug. The bug is that the social tools which have the MiniAjaxUpload component (FanBoxes, PictureGame, PollNY, QuizGame) don't take the possibility of local uploads being disabled (in favor of shared uploads, for example) into account. We could probably either tweak this bug's title to reflect that or file a new bug.

MinjAjaxUpload's non-recognition of shared uploads prevents these extensions from working 100% properly, so I suppose we should file a new bug report.

Wouldn't they have to be added to the dropdown manually? MWChat's emoticons list is different from Wikia's list, where every possible "code" was under one file url, but here, each emoticon "code" is listed under its own file, even if they're the same. Example:
* :P NE3-1.gif
* :-P NE3-1.gif
Those both use NE3-1.gif, but are activated by different "codes".

I like @ashley's ideas. That's probably the most practical approach to the issue.

Do you mind linking an example of which pages are affected?

The top header and toolbar dropdown menus look fine to me, but the search dropdown does look out-of-place. Perhaps it should share the same colour as the depressed search button.