Issue has been solved.
A mix-up with the work-PC. On that PC there was no C:\programfiles (x86)\Arduino\Libraries\RobotIRremote\IRremoteTools.cpp file, it was present on my home PC. For my home PC the LIFA base program was copied from another PC.
I had re-installed Arduino and found an original LIFA_base.ino file on my own PC. This file can be compiled without any issue.