In a testwiki, putting
{{#babel:ku-Arab-5}}
in a page, and selecting "Save" yields:

Fatal error: Cannot redeclare class SkinMonoBook in .../testwiki/phase3/skins/MonoBook.php on line 48

and selecting "Preview" yields:

Enne Fääler es opjefalle en dä Süntax vun ennem Befääl för de Datebank. Dat künnd_enne Fääler em Wikki-Projamm sin. De läzde Date_Bank_Befääl eß jewääse:

SELECT in_from FROM `tst_indexes` WHERE in_namespace = '14' AND in_title = 'Testwiki:Metmaacher_kann_كوردي_(عەرەبی)'

uß dä Funkzjohn: „IndexFunction::newFromTitle“. De Datebank mälldt dä Fääler: „1267: Illegal mix of collations (latin1_bin,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '=' (localhost)“.

Backtrace:

#0 .../testwiki/phase3/includes/db/Database.php(746): DatabaseBase->reportQueryError('Illegal mix of ...', 1267, 'SELECT in_from...', 'IndexFunction::...', false)
#1 .../testwiki/phase3/includes/db/Database.php(1051): DatabaseBase->query('SELECT in_from...', 'IndexFunction::...')
#2 .../testwiki/phase3/extensions/IndexFunction/IndexFunction_body.php(24): DatabaseBase->select('indexes', 'in_from', Array, 'IndexFunction::...')
#3 .../testwiki/phase3/extensions/IndexFunction/IndexFunction_body.php(150): IndexFunction::newFromTitle(Object(Title))
#4 [internal function]: IndexFunctionHooks::blueLinkIndexes(Object(SkinModern), Object(Title), Array, '????????????', Array, NULL)
#5 .../testwiki/phase3/includes/Hooks.php(237): call_user_func_array(Array, Array)
#6 .../testwiki/phase3/includes/Hooks.php(38): Hooks::run('LinkEnd', Array)
#7 .../testwiki/phase3/includes/Linker.php(211): wfRunHooks('LinkEnd', Array)
#8 .../testwiki/phase3/includes/Linker.php(1951): Linker->link(Object(Title), '????????????', Array, Array, 'broken')
#9 .../testwiki/phase3/includes/parser/LinkHolderArray.php(362): Linker->makeBrokenLinkObj(Object(Title), '????????????', '')
#10 .../testwiki/phase3/includes/parser/LinkHolderArray.php(238): LinkHolderArray->replaceInternal('<h2> <span clas...')
#11 .../testwiki/phase3/includes/parser/Parser.php(4469): LinkHolderArray->replace('<h2> <span clas...')
#12 .../testwiki/phase3/includes/parser/Parser.php(330): Parser->replaceLinkHolders('<h2> <span clas...')
#13 .../testwiki/phase3/includes/EditPage.php(2015): Parser->parse('== Babel ==?{<n...', Object(Title), Object(ParserOptions))
#14 .../testwiki/phase3/includes/EditPage.php(1289): EditPage->getPreviewText()
#15 .../testwiki/phase3/includes/EditPage.php(477): EditPage->showEditForm()
#16 .../testwiki/phase3/includes/EditPage.php(334): EditPage->edit()
#17 .../testwiki/phase3/includes/Wiki.php(536): EditPage->submit()
#18 .../testwiki/phase3/includes/Wiki.php(69): MediaWiki->performAction(Object(OutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#19 .../testwiki/phase3/index.php(104): MediaWiki->performRequestForTitle(Object(Title), Object(Article), Object(OutputPage), Object(User), Object(WebRequest))
#20 {main}

Version: unspecified
Severity: major