If you have encountered 500 Internal Server Error on your website, there may be a couple of reasons for that.

Lack of the PHP support

Check, whether or not the PHP support is enabled.

cPanel

In cPanel, PHP is enabled constantly.

ISPmanager

  1. Under WWW-domains, click on your domain
  2. Click Edit.DS_060617_996c85
  3. Under Additional features check the PHP box.DS_060617_6db787

PHP configuration files are corrupted

cPanel

If this error has arisen in cPanel, ask the hosting administration to fix it. PHP configuration files are unavailable to the users in cPanel and thus can be restored only by the administrator.

ISPmanager

    1. Under WWW-domains, click on your domain
    2. Click Edit.DS_060617_996c85
  1. Under the Additional features uncheck the PHP box.DS_060617_49a12a
  2. On the sidebar, under the Main Features click on the File manager.DS_060617_025cc8
  3. Click on the php-bin folder
  4. Click DeleteDS_060617_293f44
  5. Click ОК
  6. Go back to the domain settings and check the PHP box back.

Incorrect PHP version

Internal Server Error 500 can arise when the hosting is using a PHP version that is not supported by the CMS.

cPanel

  1. Log into cPanel.
  2. Under the Software click Select PHP version.DS_060617_eee8c51
  3. Choose the PHP version and click Set as current.DS_060617_73ee71
  4. Click Save.

ISPmanager

  1. Under WWW, click PHPDS_060617_1f94a1
  2. Click PHP versionDS_060617_b90c39
  3. Choose the PHP version
  4. Click OKDS_060617_988e55

.htaccess attempts to control PHP

On Unihost servers, PHP is working not as an Apache module, but as a CGI-application. This was done to improve the security. But some CMSs do not understand this solution and attempt to control PHP via the .htaccess file. This, in turn, causes the 500 Internal Server Error.

cPanel

  1. Click File ManagerDS_060617_f87fdc
  2. Click SettingsDS_060617_fb7852
  3. Click Show Hidden Files (dotfiles)
  4. Click SaveDS_060617_930772
  5. Double click on the public_html folder to open itDS_060617_ba83d8
  6. Click on .htaccess
  7. Click EditDS_060617_1f1019
  8. Delete all the lines that begin with php
  9. Click Save changesDS_060617_4a0031

ISPmanager

  1. Under the Main Features click File managerDS_060617_025cc8
  2. Double click on the www folder to open itDS_060617_f52b8c
  3. Double click on the folder with your domain name to open it
  4. Double click on the .htaccess fileDS_060617_5cd2df
  5. Delete all the lines that begin with php
  6. Click ОК.

Issues with registration

If the Internal Server Error 500 arises during the registration on the website or sending an e-mail through the contacts form, then you have to follow the manual: Problem with a website registration and e-mail notifications (500 Internal Server Error)

Not enough resources on the hosting

500 Internal Server Error can be an evidence of your website using more resources than is permitted by your hosting plan.

cPanel

  1. Click CPU and concurrent connection usage under Metrics.DS_060617_f13146
  2. Click Details

ISPmanager

  1. Click CloudLinux Limits under Statistics on the sidebarDS_060617_a8f308

If your website is using more resources than it is allowed to, contact the Unihost support to upgrade your plan or contact your website developer in order to optimize it.

If the problem still is not fixed, contact the Unihost tech support at support@unihost.com