A solution to this error is similar to the simlink solution to some of the previous library not found problems. I could not find any other forum posts with a solution, here or elsewhere.
[codebox]ln -s /usr/lib/libGL.so.1 /usr/lib/libGL.so[/codebox]
This is a simlink to a simlink to a real file & may not be good practice.
This a workaround to a problem & not a root cause fix.
Hope this helps other beginers.