No one research new units- Sandbox Game

[Asimov]

Hi, I am now playing a 1958 sandbox game as Taiwan and trying to buy new unit techs from the majors, but the problem is none of the countries in the world researched new units. What I am describing seems to be different from what had already been reported in relation to research technology, as I couldn't find new units being researched in the diplo screen around the world.

One would have expected to find the USA has researched F-86 Saber and the USSR has researched Mig-15 in 1958, but all the interceptor unit techs I can see in the diplo screen are the three present from the start of the game.

I wonder whether this is a bug or just a serious manifestation of the issue of research priority. Thanks.

[Balthagor]

Or, you haven't researched the non-tradable prerequisites needed to see those designs.

[barkhauer]

Or, you haven't researched the non-tradable prerequisites needed to see those designs.

Bingo.

[Asimov]

Many thanks for the prompt replies, gentlemen. So minor powers trying to catch up tech wise would have bumped into a glass wall, which is partially mitigated by the sales of advanced units from friendly countries?

Also, is it still possible to change to play other countries by using the multiplayer mode in SRCW? Thanks.