I believe the original README with the V4.1 client said that if you are
upgrading from V3 to V4, you should UNINSTALL the 3.1.x client first, then
install the V4 client from scratch.

Then if you are going from any 4.1 to any 4.2, you should be able to just
put on the latest patch level.

The clients are SUPPOSED to be self-contained so you just install any patch
level and that includes everything you need; the only case I remember where
they said you should uninstall first is when going from V3 to V4.

So I would try installing 3.1.0.6, then installing 4.2.1.18.  If that
doesn't work, I would report it as a problem.

************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
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