Preview in Admin Plugin broken

[TobiasScheinert]

Hi,

Version 1.7.0 works

---------------------------------------------------------------
| Count | Name         | Slug  | Version          | Installed |
===============================================================
| 1     | Admin Panel  | admin | v1.7.0 -> v1.7.1 | installed |
---------------------------------------------------------------

after an upgrade:

------------------------------------------------------
| Count | Name         | Slug  | Version | Installed |
======================================================
| 1     | Admin Panel  | admin | v1.7.1  | installed |
------------------------------------------------------

0 - An exception has been thrown during the rendering of a template ("Undefined index: HTTP_REFERER").

Log output:

[2018-03-19 22:43:46] grav.CRITICAL: An exception has been thrown during the rendering of a template ("Undefined index: HTTP_REFERER"). - Trace: #0 /path/to/webpage/cache/twig/f0/f06ae2f5b2803384507c810b0c39e41f628ed5ee8ccf6e87cb7440dcf1bca162.php(195): Twig_Template->displayBlock('titlebar', Array, Array)
#1 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(215): __TwigTemplate_971c1000ff0ad781c34e7a9b752181f10b47bed1688dcc756b57404e69ec239d->block_page(Array, Array)
#2 /path/to/webpage/cache/twig/f0/f06ae2f5b2803384507c810b0c39e41f628ed5ee8ccf6e87cb7440dcf1bca162.php(167): Twig_Template->displayBlock('page', Array, Array)
#3 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(215): __TwigTemplate_971c1000ff0ad781c34e7a9b752181f10b47bed1688dcc756b57404e69ec239d->block_body(Array, Array)
#4 /path/to/webpage/cache/twig/f0/f06ae2f5b2803384507c810b0c39e41f628ed5ee8ccf6e87cb7440dcf1bca162.php(52): Twig_Template->displayBlock('body', Array, Array)
#5 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(432): __TwigTemplate_971c1000ff0ad781c34e7a9b752181f10b47bed1688dcc756b57404e69ec239d->doDisplay(Array, Array)
#6 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(403): Twig_Template->displayWithErrorHandling(Array, Array)
#7 /path/to/webpage/cache/twig/52/52a293b76e3e1a35b7010558e8703f937ace127c0d6fb42f92fde76fa4cac9af.php(23): Twig_Template->display(Array, Array)
#8 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(432): __TwigTemplate_337c271fe17c8eab85e22cb1998aa6ccac01f465625ed066457774036a2d3832->doDisplay(Array, Array)
#9 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(403): Twig_Template->displayWithErrorHandling(Array, Array)
#10 /path/to/webpage/cache/twig/41/41a3a64d6dafc4766713a9c5e5e51a365e4d86a768aca91f39d0b86e05d48212.php(30): Twig_Template->display(Array, Array)
#11 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(432): __TwigTemplate_815a98182db53e218ad21e9f09208b0c8bf3171108aa027c44130ba467dc70cf->doDisplay(Array, Array)
#12 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(403): Twig_Template->displayWithErrorHandling(Array, Array)
#13 /path/to/webpage/vendor/twig/twig/lib/Twig/Template.php(411): Twig_Template->display(Array)
#14 /path/to/webpage/vendor/twig/twig/lib/Twig/Environment.php(363): Twig_Template->render(Array)
#15 /path/to/webpage/system/src/Grav/Common/Twig/Twig.php(349): Twig_Environment->render('preview.html.tw...', Array)
#16 /path/to/webpage/system/src/Grav/Common/Service/OutputServiceProvider.php(27): Grav\Common\Twig\Twig->processSite('html')
#17 /path/to/webpage/vendor/pimple/pimple/src/Pimple/Container.php(118): Grav\Common\Service\OutputServiceProvider->Grav\Common\Service\{closure}(Object(Grav\Common\Grav))
#18 /path/to/webpage/system/src/Grav/Common/Processors/RenderProcessor.php(19): Pimple\Container->offsetGet('output')
#19 /path/to/webpage/system/src/Grav/Common/Grav.php(132): Grav\Common\Processors\RenderProcessor->process()
#20 /path/to/webpage/system/src/Grav/Common/Grav.php(374): Grav\Common\Grav->Grav\Common\{closure}()
#21 [internal function]: Grav\Common\Grav::Grav\Common\{closure}('render', 'Render', Object(Closure))
#22 /path/to/webpage/system/src/Grav/Common/Grav.php(350): call_user_func_array(Object(Closure), Array)
#23 /path/to/webpage/system/src/Grav/Common/Grav.php(133): Grav\Common\Grav->__call('measureTime', Array)
#24 /path/to/webpage/index.php(52): Grav\Common\Grav->process()
#25 {main} [] []

I've tried to clean the cache using the admin panel and also by cleaning manually the cache folder. The web page is running under Debian Linux (Stretch) using Apache 2.4 and PHP 7.0.

Greeting Tobias

[rhukster]

Fixed in develop branch of admin