To quote the government:

«To start an association, at least two natural persons and/or legal entities are needed. No seed capital is required. It is established following an organizational meeting called to approve the association’s articles of association and to appoint its board members and auditor. The required bodies are the general assembly and the association board (at least one member).

An association is an independent legal entity. Hence, association members are not personally liable for the association’s debt.»

https://www.kmu.admin.ch/kmu/en/home/concrete-know-how/setting-up-sme/starting-business/choosing-legal-structure/associations.html

My take: It is up to your contract partners to recognize that they are dealing with an association with possibly very little liability and act accordingly.