**List of steps to reproduce** (step by step, including full links if applicable):
* create a new map with colored markers in the VE interface and save the page
* create a line manually
**What happens?**:
The [[ https://en.wikipedia.org/wiki/User:Svantje_Lilienthal_(WMDE)/sandbox/maps | map is empty ]].
{F35148612}
Error message: `Failed to parse color: \"#function fill() { [native code] }\`
See also https://wiki.alquds.edu/?query=Wikipedia:Village_pump_(technical)/Archive_189#Mapframe_showing_ocean_in_saved_page
**What should have happened instead?**:
The map should be displayed correctly with markers and the line.
**Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc.**:
Looks like the automatically created empty property field is creating an issue.