Using MediaWiki 1.18.3 and Translate 2011-07-09 (the most recent available at mw.org), problem resolves by disabling Extension:Translate in LocalSettings.php:

http://www.coincompendium.com/w/index.php?title=MediaWiki:Sidebar&action=edit

Internal error

TranslationHelpers::getSuggestionBox: Unsupported type ttmserver

Backtrace:

#0 [internal function]: TranslationHelpers->getSuggestionBox()
#1 /path/to/w/extensions/Translate/utils/TranslationHelpers.php(215): call_user_func(Array)
#2 /path/to/w/extensions/Translate/TranslateEditAddons.php(262): TranslationHelpers->getBoxes()
#3 /path/to/w/extensions/Translate/TranslateEditAddons.php(141): TranslateEditAddons::editBoxes(Object(EditPage))
#4 [internal function]: TranslateEditAddons::addTools(Object(EditPage))
#5 /path/to/w/includes/Hooks.php(216): call_user_func_array('TranslateEditAd...', Array)
#6 /path/to/w/includes/GlobalFunctions.php(3660): Hooks::run('EditPage::showE...', Array)
#7 /path/to/w/includes/EditPage.php(1390): wfRunHooks('EditPage::showE...', Array)
#8 /path/to/w/includes/EditPage.php(500): EditPage->showEditForm()
#9 /path/to/w/includes/EditPage.php(353): EditPage->edit()
#10 /path/to/w/includes/Wiki.php(515): EditPage->submit()
#11 /path/to/w/includes/Wiki.php(255): MediaWiki->performAction(Object(Article))
#12 /path/to/w/includes/Wiki.php(640): MediaWiki->performRequest()
#13 /path/to/w/includes/Wiki.php(547): MediaWiki->main()
#14 /path/to/w/index.php(57): MediaWiki->run()
#15 {main}

Version: REL1_18-branch
Severity: critical