Permission denied: /var/www/abc/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable?

Make sure that the htaccess file is readable by apache:

chmod 644 /var/www/abc/.htaccess 

And make sure the directory it's in is readable and executable:

chmod 755 /var/www/abc/

I had the same issue when I changed the home directory of one use. In my case it was because of selinux. I used the below to fix the issue:

selinuxenabled 0
setenforce 0

If it gets into the selinux arena you've got a much more complicated issue. It's not a good idea to remove the selinux protection but to embrace it and use the tools that were designed to manage it.

If you are serving content out of /var/www/abc, you can verify the selinux permissions with a Z appended to the normal ls -l command. i.e. ls -laZ will give the selinux context.

To add a directory to be served by selinux you can use the semanage command like this. This will change the label on /var/www/abc to httpd_sys_content_t

semanage fcontext -a -t httpd_sys_content_t /var/www/abc

this will update the label for /var/www/abc

restorecon /var/www/abc 

This answer was taken from unixmen and modified to fit this question. I had been searching for this answer for a while and finally found it so felt like I needed to share somewhere. Hope it helps someone.