The following warning is given when editing an HTML block.

Strict Standards: Only variables should be passed by reference in D:\xampp\htdocs\moodle_testing\blocks\edit_form.php on line 175

I noted that this happened when editing the block on the Home or My home pages, but not in courses.

The error appears on the initial configuration and subsequent edits.

Replication steps:

1. Ensure debugging messages are turned on
2. Navigate to My home
3. Click "Customise this page" button (top-right)
4. From the block drop-down list, select HTML
5. Allow page to reload and click on the configuration icon for the new block