Whatever its basis or supporting proofs, that decision and judgment thereon are not subject, as here attempted, to collateral attack. Sablain v. National Refining Co., 289 Mich. 269. See, also, Adams v. Adams, 304 Mich. 290; Life Insurance Company of Detroit v. Burton, 306 Mich. 81; Rarden v. R.D. Baker Co., 279 Mich. 145. Defendant attacks the probate court proceedings on the ground that that court, in allowing plaintiff to present its tardy claim, did not limit the time therefor to 1 month as directed in CL 1948, § 708.18 (Stat Ann § 27.3178[428]), and further that the judgment of the tax court was not certified, as in CL 1948, § 708.23 (Stat Ann § 27.3178[433]), provided, "to the probate court."