Pull Request resolves # .

• I read the Generative AI policy and my contribution is either not created with the help of AI or is compatible with the policy and GNU/GPL 2 or later.

Summary of Changes

Currently, when you access to a file in template manager (image, font, or archive), there is a warning in PHP error logs like below:

[20-Aug-2026 12:17:53 UTC] PHP Warning: Attempt to read property "filename" on null in D:\www\joomla\administrator\components\com_templates\tmpl\template\default.php on line 72

This PR just fixes that simple issue.

Testing Instructions

• Uses Joomla 5.4
• Go to System -> Global Configuration, set Error Reporting to Maximum
• Access System -> Site Templates, click on a template to go to Template Manager screen
• From template manager screen for that template, access to an image file (for example media/templates/site/cassiopeia/images/template_preview.png)
• Check PHP error logs (the warning not displayed in the screen because the output for the code is hidden and that's why you need to check PHP error logs to see warning)

Actual result BEFORE applying this Pull Request

• You see warning like below

[20-Aug-2026 12:17:53 UTC] PHP Warning: Attempt to read property "filename" on null in D:\www\joomla\administrator\components\com_templates\tmpl\template\default.php on line 72

Expected result AFTER applying this Pull Request

• No warning anymore

Link to documentations

Please select:

• Documentation link for guide.joomla.org:

• No documentation changes for guide.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed