When you uninstalled the older version, did you keep the plugins folder? If not you will have to reobtain the decomb plugin you were using beforehand.
I'm not exactly sure what in all comes with the amvapp cause last I used it was many years ago but I'm going to take a guess that it doesn't provide the decomb plugin anymore or at all, instead probably TIVTC meaning you would use TFM instead of telecide. Try taking out the Telecide line, if Tdecimate works still then you have TIVTC/TFM plugin loading but no decomb plugin which is what you were used to using on the old org app hence why telecide isn't working.
You can confirm also by just checking your plugins folder and telling us what plugins are still there. Here's the old plugin you were using:http://avisynth.org/mediawiki/Decomb
"The people cannot be [...] always, well informed. The part which is wrong will be discontented, in proportion to [...] the facts they misconceive. If they remain quiet under such misconceptions, it is lethargy, the forerunner of death to public liberty. What country can preserve its liberties, if it's rulers are not warned [...] that this people preserve the spirit of resistance? The tree of liberty must be refreshed from time to time, with the blood of patriots and tyrants."-Thomas Jefferson