I try to include PHP file from different places of my computer. So I have defined different include paths in my php.ini
Warning: require_once(X:\project\b\file_b.php): failed to open stream: No such file or directory in C:\project\a\file_a.php on line 2
Fatal error: require_once(): Failed opening required 'X:\project\b\file_b.php' (include_path='.;C:\project\a;X:\project\b') in C:\project\a\file_a.php on line 2
Abort Processing during Fatal-Error: require_once(): Failed opening required 'X:\project\b\file_b.php' (include_path='.;C:\project\a;X:\project\b') Error in Script C:\project\a\file_a.php on Line 2
After a long time, I have finally the answer for my special problem.
It is really ery special, because I use BoxCryptor to encrypt my D: drive. BoxCryptor creates the virtual device X:, but it is not present for Apache and PHP. But I can configure BoxCryptor the mount the device X: as a rwal harddrive. After I set this, everythings works fine.
Sorry for the confusion about my vortual and real harddrives and thank you for your help!
Best regards, bition