An exception occurred: [ErrorException] [E_WARNING] Cannot modify header information - headers already sent by (output started at /src/addons/XenGenTr/XGTStyleV12/XF/Template/Templater.php:20) in src/addons/XenGenTr/XGTStyleV12/XF/Template/Templater.php on line 39

1. XF::handlePhpError()
2. header() in src/addons/XenGenTr/XGTStyleV12/XF/Template/Templater.php at line 39
3. XenGenTr\XGTStyleV12\XF\Template\Templater->setGroupStyles() in src/XF/App.php at line 2232
4. XF\App->setupTemplaterObject() in src/XF/App.php at line 1589
5. XF\App->{closure:XF\App::initialize():1587}() in src/XF/Container.php at line 33
6. XF\Container->offsetGet() in src/XF/App.php at line 1599
7. XF\App->{closure:XF\App::initialize():1596}() in src/XF/Container.php at line 33
8. XF\Container->offsetGet() in src/XF/App.php at line 3819
9. XF\App->cssWriter() in css.php at line 21