Plan Amendment Effective, but Late Adopted

Plan was amended effective Jan. 1, 2018 and plan was operated in accordance with these amendments.  For some reason, the actual amendment was signed and adopted until April 2019.  Is there an issue and if so how is it corrected?
 

If statutory changes, probably OK, but if discretionary changes then VCP is the proper way to go. If the amendment was a reduction or limitation compared to prior revision, you'll likely need documentation of all the other steps completed in a timely manner, such as board resolution, employee communications, vendor communications, etc. demonstrating timely employer intent and (with the exception of signature) execution.

BenefitsRUs21, I agree with CuseFan, but would add that it, e.g., this is a corporation and you have a board resolution adopted (e.g., by unanimous consent or at a meeting of directors) before end of 2018, that may be enough for adoption. Depending on the entity's type and governance, adoption may occur before signature by officer on amendment. often, however, signature is all you have, so the foregoing may not be relevant to your situation.