I have created a pure Python project in PyCharm and imported numpy, tensorflow and opencv in order to test a small program. <
In my case it was obsolete pyqt library. This following worked for me.
conda install -c anaconda pyqt
The problem does not come from PyCharm, if you use any other IDEs, the result would be the same. In fact, they all use a package called pydev to debug. Your best bet would be to create a brand new Python environment (PyCharm has a function for this) and gradually install packages.
If the solution works and you can find out which package conflicts with pydev, it will be most helpful.
This was solved by installing pyqt. I installed pyqt with the command (from conda-forge)
conda install -c conda-forge pyqt