Premature end of script headers: index.php

I updated to v2.8.1 (automatic update) and now some widgets on the dashboard are not displayed anymore - instead the error message “Oops… während der Anfrage ist ein Problem aufgetreten. Möglicherweise war der Server temporär überlastet, oder eventuell haben Sie einen Bericht mit zu vielen Daten angefordert. Bitte noch einmal versuchen. Wenn dieser Fehler wiederholt auftritt kontaktieren Sie bitte Ihren Piwik Administrator um Unterstützung zu erhalten.” is shown.
I searched the web for similar problems and contacted my hoster which said everything seems to be ok on his side and he thinks that something within index.php is faulty.
I compared index.php on my server with a freshly downloaded package from piwik.org and the file content is the same.

Anyway I am getting a syntax error warning for line 40 (using an old Dreamweave editor though):
\Piwik\Loader::init();

can anyone help please?

in your server error log file, do you see any error?

thanks for your reply! seemed like a temporary issue though - piwik is working again as normal today!
great product by the way - use it as default tracking tool on all websites I install :wink: