When I open up the Tracking Center and open up KER to find an interplanetary transfer window, there is no info available. However, rendezvous info is present if I am piloting a spacecraft. I have already tried removing all other mods, but the problem seems to be in KER.

Here is a screenshot:

Are you setting the ship as the reference?

Noticed the same problem, is fixed for me too. Thanks!

No. Kerbin is the reference orbit. I have even tried setting the ship as the reference, which did not fix the problem. There is also no information if I set the ship as the reference and target one of Kerbin's moons.

OK I think I got it sorted. See if this fixes everything. Thanks for the report.
KerbalEngineer-1.1.5.1.zip

It works! I can now see the rendezvous information in the Tracking Center. If you are going to release that as a new version, should I download the mod from the main page, or can I just keep that file?

Thanks for all of your hard work!

it'll be the same file