Question: I'm having a problem updating php in Linux Redhat.
I updated by

```
yum install php56w

```

But it says there's no repository for php56w.
So I updated httpd by 

```
yum update httpd

```

But since then, all websites(which is using php) are not working, they're showing 500 Internal server error.
This seems to be permission error, but I've no idea how to fix.
Anyone please help.

Answer: 
Which RHEL version?

If it's RHEL 6 and you're upgrading the PHP version, you should use the PHP 5.6 software collection (<https://access.redhat.com/products/Red_Hat_Enterprise_Linux/Developer/#dev-page=5>). 

If it's RHEL 7 - I don't recall the default PHP version. :/
If you want PHP versions which are not considered stable enough by RedHat you will need to enable the EPEL repository and then install php like you tried before.

Do the following for enabling EPEL repo, make sure you are a root user:

ON RHEL/CentOS 7 64 Bit:

```
wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-9.noarch.rpm

rpm -ivh epel-release-7-9.noarch.rpm

```

[For more information check this site about EPEL](https://www.tecmint.com/how-to-enable-epel-repository-for-rhel-centos-6-5/)