I just revisited an Etherpad Lite instance after some time, and somehow my database got deleted. So obviously the pad I tried to access at first raised an error.

We should handle the error instead of dying, else migrating to a different EPL installation will be nearly impossible.

Text of error:

Unexpected non-MediaWiki exception encountered, of type "InvalidArgumentException"
exception 'InvalidArgumentException' with message 'padID does not exist' in /home/administrator/projects/EtherEditor/includes/EtherpadLiteClient.php:93
Stack trace:
#0 /home/administrator/projects/EtherEditor/includes/EtherpadLiteClient.php(74): EtherpadLiteClient->handleResult(Object(stdClass))
#1 /home/administrator/projects/EtherEditor/includes/EtherpadLiteClient.php(34): EtherpadLiteClient->call('setText', Array, 'POST')
#2 /home/administrator/projects/EtherEditor/includes/EtherpadLiteClient.php(246): EtherpadLiteClient->post('setText', Array)
#3 /home/administrator/projects/EtherEditor/EtherEditorHooks.php(120): EtherpadLiteClient->setText('g.Kzttc59cKsvNy...', 'This is a test!...')
#4 [internal function]: EtherEditorHooks::editPageShowEditFormInitial(Object(EditPage), Object(OutputPage))
#5 /home/administrator/projects/mediawiki/includes/Hooks.php(255): call_user_func_array('EtherEditorHook...', Array)
#6 /home/administrator/projects/mediawiki/includes/GlobalFunctions.php(3871): Hooks::run('EditPage::showE...', Array)
#7 /home/administrator/projects/mediawiki/includes/EditPage.php(2042): wfRunHooks('EditPage::showE...', Array)
#8 /home/administrator/projects/mediawiki/includes/EditPage.php(421): EditPage->showEditForm()
#9 /home/administrator/projects/mediawiki/includes/actions/EditAction.php(51): EditPage->edit()
#10 /home/administrator/projects/mediawiki/includes/Wiki.php(439): EditAction->show()
#11 /home/administrator/projects/mediawiki/includes/Wiki.php(305): MediaWiki->performAction(Object(Article), Object(Title))
#12 /home/administrator/projects/mediawiki/includes/Wiki.php(565): MediaWiki->performRequest()
#13 /home/administrator/projects/mediawiki/includes/Wiki.php(458): MediaWiki->main()
#14 /home/administrator/projects/mediawiki/index.php(59): MediaWiki->run()
#15 {main}

Version: master
Severity: normal