While trying to download highlighting files I get:

The list of highlightings could not be found on / retrieved from the server

The URL is http://kate-editor.org/syntax/update-5.19.xml

http://kate-editor.org/syntax/update-5.17.xml is OK, but 5.19 is missing.

Reproducible: Always

Steps to Reproduce:
1. Open Kate
2. Go to menu Settings - Configure Kate
3. Select at the left Editor Component - Open/Save
4. At the right, on "File Opening & Saving", select the third tab "Modes & Filetypes"
5. Press "Download Highlighting files..."

Actual Results:  
An error box is shown with the following error:
The list of highlightings could not be found on / retrieved from the server

Expected Results:  
The Highlight Download window should be populated with all the available syntax highlighting files.

From the About box:

Kate Version 15.12.1

Using:
KDE Frameworks 5.19.0
Qt 5.5.1 (built against 5.5.1)
The xcb windowing system

On Fedora 23