With tips from @Mark Hall and @Dev Banerjee, we were able to fix the problem.
With the tip of our masters, look at the problem in the .log file in the .metadata folder of the workspace that the problem was.
I found the error below:
java.lang.RuntimeException: Error initializing file: EGLSource/br/com/morlan/rui/common/rn/records/MaintActive.egl
Looking at the facts, we saw that the team modified the MaintActive.egl source package,
The MaintActive.egl file was linked in several projects, and the link was lost because the SOURCE is no longer in the folder. (Strange that it was to point out an error in the project and that didn't happen leaving us lost).
So, by eliminating the wrong folder link and leaving the link to the correct folder, we solve the problem for all projects.
Thus, all the eclipse functionalities are back to work.
However, I wonder why the eclipse behaved in this way.
Thank you all.