Error Codeigniter PHP could not open the stream: Rights denied

i agree with @php_rocs that would be one thing to check. Linux has some quirks and then when you add something that is not "technically" installed on system thats why its in opt such as xampp hten that adds further quirks.

So assuming T_Project is your web dev then open a terminal and use these commands:

Code:

cd /opt/lampp/htdocs

sudo ls -ld  T_Project
//come back with output please

generally directories should be 755 and files 644 . I had a problem with index.php in public directory of CI4.0.4 ; chmod was 777, the server didn't like it. I changed it to 644 and that fixed issue.

Now the other thing i wondering is the index.php which has more than 200 lines, as indicated by your error. Not sure which Ci your using but index.php in public of Ci4 is only circa 50 lines long. There is an index.php of xampp and i'm wondering if thats getting involved.