I am assuming you have the latest build of 15 installed (3267).
Was Ecodesigner installed before or after this hotfix?
If after then it may be worth just trying to re-install the hotfix.
I know the hotfixes updates the goodies but I am not sure if it also updates addons like Ecodesigner.
It might be worth a try before re-installing Archicad.
One of the forum moderators. Versions 6.5 to 27 Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10 Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11