(a) Except as otherwise provided in subsection (b) of this section, venue for a judicial proceeding involving a trust is in the probate district of this State in which the trust's principal place of administration is or will be located and, if the trust is created by will and the estate is not yet closed, in the probate district in which the decedent's estate is being administered.(b) If a trust has no trustee, venue for a judicial proceeding for the appointment of a trustee is in a probate district of this State in which a beneficiary resides, in a probate district in which any trust property is located, and if the trust is created by will, in the probate district in which the decedent's estate was or is being administered.