Hey Community,
Yesterday I put my page online that I built locally on MAMP. Everything went well, only the panel is not reachable anymore since the upload on the ftp. When i go on mysite.de/panel it only shows me a blank google chrome page with the link http://panel/login.
All issues i found in the forum or in the docs, i’ve checked … still no access to the panel 
Done:
Can someone help me there?
Have you enabled debugging? Or can you see any errors in the PHP error log?
And have you made sure the mb_string extension is enabled?
You can either enable debugging in your config.php (temporarily only) or you check your php.ini settings if you are familiar with that. Usually, on a production server, debugging should be enabled, but errors shouldn’t be displayed on screen but saved to a log file.
Im not so familiar with the php.ini settings …
Where can i find the log file?
Check phpinfo(); it should tell you where to find the log file, in the core section under error_log. There might not be any, if the hosting provider doesn’t provide it. But as I said, temporarily you can try to enable debugging in your config.
Do subpages work?
Have you tried re-uploading the panel?
Do you use any plugins?
What is your PHP version?
All subpages work.
Will try to re-upload the panel 
Only the plugins embed and logger.
PHP-Version is PHP Version 7.0.27.
Edit: No changes with reupload the panel
Does the same happen with a fresh StarterKit?
Have to try this!
What reason it can be when the browser throws me the link http://panel/login?
Oh, sorry, I overlooked the missing domain. Are you using any additional redirects somewhere? Have you tried to set the URL in your config?
Oh, sorry, I overlooked the missing domain. Are you using any additional redirects somewhere?
Nope
Have you tried to set the URL in your config?
How can i set it? With RewriteBase / and the foldername?
c::set('url', 'http://yourdomain.com');
If that doesn’t help, try with commenting out the RewriteBase.
Both variants do not bring any change 
I’m very mad atm.
What hosting provider are you on? Strato?
The provider of my customer is strato.
See this thread for a solution to this problem with Strato hosting: Error: idn_to_ascii() expects at most 2 parameters, 3 given
Changed the lines in kirby/vendor/getkirby/toolkit/lib/url.php to
384 $host = idn_to_utf8(static::host($url));
405 $host = idn_to_ascii(static::host($url));
and now it works!
Thank you sooooo much @texnixe!