When I start FME it reports that I have duplicate coordinate systems and closes down - what is the problem

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Q) When I start FME it reports that I have duplicate coordinate systems and closes down - what is the problem?

A) The current situation is that duplicate coordinate systems are not permitted, and the issue is serious enough to stop FME. Fortunately this is very rare.

If this arises check for duplicate coordinate systems in LocalCoordSysDefs.fme, MyCoordSysDefs.fme and the folder <my documents>/fme/CoordinateSystems. Also check that <my documents>/fme/CoordinateSystems has not been also added as a Shared Resource using Tools > Options > Shared Directories. FME scans this automatically and if you add it as a shared directory as well then any coordinate systems contained within it will automatically count as duplicated.