for your interest. It was the ‘Claue sample data’ plugin that caused a big memory usage and resulted in the server error. No problem of course, since the plugin is only used for first setup. We have now deactivated this plugin and everything works fine now.
thanks for the reply. These settings did not resolve the issue, but somehow I am not getting empty pages anymore but a HTML error 503 (service unavailable).
I made a mistake with the domain credentials, can I send new ones?