Error message

When I try to get OpenMx from the RGui, I get the following message:
Warning: unable to access index for repository https://openmx.ssri.psu.edu/packages/bin/windows64/contrib/2.11
Warning message:
In getDependencies(pkgs, dependencies, available, lib) :
package ‘OpenMx’ is not available

Not sure what the problem is, please advise...

DJ