new error when importing ical

[punkyard]

hi
so far, my external links worked - emitted by nextcloud
.. not anymore: error!

i tried to create a new external calendar, but i got an error.
I tried with a previous link, which worked previously, I get also an error.

I went to the logs, and discovered a long long list of errors, like this one:

Thu, 22 Dec 2022 20:10:01 +0100 application yii\base\InvalidValueException: Error while creating ical... Check if link is reachable. in /home/protected/modules/external_calendar/models/ICalSync.php:80 Stack trace: #0 /home/protected/modules/external_calendar/models/ICalSync.php(68): humhub\modules\external_calendar\models\ICalSync->syncICal() #1 /home/protected/modules/external_calendar/models/ExternalCalendar.php(408): humhub\modules\external_calendar\models\ICalSync::sync() #2 /home/protected/modules/external_calendar/jobs/SyncHourly.php(27): humhub\modules\external_calendar\models\ExternalCalendar->sync() #3 /home/protected/humhub/modules/queue/ActiveJob.php(33): humhub\modules\external_calendar\jobs\SyncHourly->run() #4 /home/protected/vendor/yiisoft/yii2-queue/src/Queue.php(246): humhub\modules\queue\ActiveJob->execute() #5 /home/protected/vendor/yiisoft/yii2-queue/src/cli/Queue.php(147): yii\queue\Queue->handleMessage() #6 /home/protected/vendor/yiisoft/yii2-queue/src/drivers/db/Queue.php(83): yii\queue\cli\Queue->handleMessage() #7 [internal function]: yii\queue\db\Queue->yii\queue\db\{closure}() #8 /home/protected/vendor/yiisoft/yii2-queue/src/cli/Queue.php(117): call_user_func() #9 /home/protected/vendor/yiisoft/yii2-queue/src/drivers/db/Queue.php(93): yii\queue\cli\Queue->runWorker() #10 /home/protected/vendor/yiisoft/yii2-queue/src/drivers/db/Command.php(56): yii\queue\db\Queue->run() #11 [internal function]: yii\queue\db\Command->actionRun() #12 /home/protected/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array() #13 /home/protected/vendor/yiisoft/yii2/base/Controller.php(178): yii\base\InlineAction->runWithParams() #14 /home/protected/vendor/yiisoft/yii2/console/Controller.php(182): yii\base\Controller->runAction() #15 /home/protected/vendor/yiisoft/yii2/base/Module.php(552): yii\console\Controller->runAction() #16 /home/protected/vendor/yiisoft/yii2/console/Application.php(180): yii\base\Module->runAction() #17 /home/protected/vendor/yiisoft/yii2/console/Application.php(147): yii\console\Application->runAction() #18 /home/protected/vendor/yiisoft/yii2/base/Application.php(384): yii\console\Application->handleRequest() #19 /home/protected/yii(29): yii\base\Application->run() #20 {main}

my ical links work in my phone and pc client
I'm using HH 1.12.2

could you help me out with this?
thanks a lot