But there is config-defaults.php is it the same?
When I start instalation of LS (....limesurvey/admin) on web server there is:
Warning: require_once(application/Psr4AutoloaderClass.php): failed to open stream: No such file or directory in /home/mirena1/ftp/ci/index.php on line 183
Fatal error: require_once(): Failed opening required 'application/Psr4AutoloaderClass.php' (include_path='.:/usr/share/php:/usr/share/pear') in /home/mirena1/ftp/ci/index.php on line 183
Last time (few months ago) I was installing LS without any problems
config-defaults.php is the base configuration, the defaults that LS will fall back to if they are NOT configured in config.php. Never change anything in config-defaults.php, but rather in config.php. If there is a configuration that you would like to change and it is not yet in config.php, copy it from config-defaults into config and change it there.
Help us to help you!
Provide your LS version and where it is installed (own server, uni/employer, SaaS hosting, etc.).
Always provide a LSS file (not LSQ or LSG).
Note: I answer at this forum in my spare time, I'm not a LimeSurvey GmbH employee.