Never used this, but from what I understand, "Soft" gives you a warning, but you can ignore it and continue. Why don't you just try it on one of your questions and see what happens?
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Provide your LS version and where it is installed (own server, uni/employer, SaaS hosting, etc.).
Always provide a LSS file (not LSQ or LSG).
Note: I answer at this forum in my spare time, I'm not a LimeSurvey GmbH employee.