Eclipse is telling me a cycle was detected in the building path, but that's not true!

Question

Eclipse is telling me:

a cycle was detected in the build path of -project name-

, although the structure of the project (created by others in the team) does not have cycles.
The same project is deployed on other machines (the same!) and it doesn't give the error.

I need to work from my machine so I need to solve this.
It is giving me the error in 8 different projects.
It was giving me the error in more (10 projects) but with cleaning and building 10 times just changed to 8! (without any changes in the code).

I really need to get this working and cleaning and building over and over is not doing anything. Any tips?

(note: this is not java, this is flex so i can't change the error to warning :))

Thanks a lot!

Solution

If it works on other machines but not your own, it must be a "local cache" effect.

You must have an existing library taken into account from a long time, which causes locally the error, while that same file is not present on the other workstations.

Could try and recreate the projects from scratch, on a new empty directory, and see if the problem persist?
If it does (and only then), the exact version of Eclipse and Flex plugin could help.