[PyMOL] cannot write text commands after pymol-open-source installation

I am encountering a strange problem. After building the latest
pymol-open-source from github on Ubuntu 19.04 and Python 3.7.3 I am not
able to write text commands. It seems that PyMOL does not receive input
from the keyboard because neither the arrow buttons ->, <- work for moving
to the next and previous molecules in a multi-mol file. Does anyone
encounter a similar problem? Any idea how to fix this?

Thanks in advance.
Thomas

-- 

======================================================================

Dr. Thomas Evangelidis

Research Scientist

IOCB - Institute of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences <," rel="nofollow">https://www.uochb.cz/web/structure/31.html?lang=en>, Prague,
Czech Republic
  &
CEITEC - Central European Institute of Technology
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Czech Republic

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