Urgently report an error and ask for help:variable ‘candidate’ of type ‘xxxx’ referenced from scope ”, but itxxxxx

When I use lamdba expressions to query data, the writing is like this:
var exp = CreateExpression<AlterApply>();

orgCode = "123456789";

exp = exp.AndAlso(t => orgCode.Contains(t.OrgCode));

Write like this wil…