I believe the original channel map
always used the Kronstadt01 plate. Either that, or there were edited versions in circulation which did. The other way to obtain "smooth" or "frictionless" airfields back in the day was "Zuti's Friction Mod" - an entirely different method not dependent on plate objects.
Some versions of the game included the
blank version of the Kronstadt01 plate by default, for example UltraPack 2 (I think). Some object packs also included the blank plate, because they had been extracted from large mod packs which also included the blank plate.
So, if by chance, you had a map with Kronstadt01 plates,
and a game version with blank versions of the plate - happy days.
If not, you need to install a blank version of the plate into your mods folder, and everything works.
The downside of this solution, as Istvan points out, is that it messes up the stock Gulf of Finland map that the original non-blank Kronstadt01 plate was designed for. In which case the player can easily disable the blank plate in his mod folder if he wants to use the stock Gulf of Finland map. The long term fix, however, is to edit modified maps that utilise "blank" Kronstadt01 plates to use a custom blank plate that
doesn't effect the stock Kronstadt01 plate.
If this is a
new bug in C.U.P., either a different version of the map has been installed (one with Kronstadt01 plates)
or a "blank" version of the Kronstadt01 plate has been overwritten with a "stock" version.
That's a bit of a long-winded explanation, but I hope it helps?
KB