[Owncloud] Error code 200 during CalDAV sync

[Advrk Aplmrkt]

Hello,

I've recently updated my ownCloud to most recent Git. But now when I
synchronise my calendars with it via Thunderbird 10.0.2, I get the
following error:

Status Code: 200, The request cannot be processed.

[Error message: Could not execute statement]
[Last executed query: ALTER TABLE oc_appconfig RENAME TO __oc_appconfig]
[Native code: 1]
[Native message: there is already another table or index with this
name: __oc_appconfig]
[Error message: Could not execute statement]
[Last executed query: CREATE  TABLE "oc_appconfig" ("appid"
VARCHAR(255) DEFAULT '' NOT NULL, "configkey" VARCHAR(255) DEFAULT ''
NOT NULL, "configvalue" LONGTEXT NOT NULL)]
[Native code: 1]
[Native message: table "oc_appconfig" already exists]
Error while upgrading the database

What does this mean? And how can I troubleshoot this? Thanks!