I'm guessing the 2 problems are unrelated.
The validation error, which disappears after a restart, should not occur in newer versions of Tersus (I presume you're using the last stable version, 1.3.59), and in any case was insignificant.
The onchange issue, is probably some spelling (or other) mistake in your model. Double check that the Year Number Input Field, contains an <On Change> action (the spelling and case of the latter are significant).
An easy way to verify that the <On Change> is being fired, is to temporarily add an alert to it (alongside the existing modelling), as in the following screenshot:
If you cannot resolve this issue, you're welcome to post your own screenshot, or export and attach a demo project.
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