KartSim for rFactor 2 - Unknown Base Mod Missing?

I just bought and downloaded KartSim for rFactor2. However, the only karts available to me are the Rental Karts. (All 3 tracks are available however.) When Steam workshop syncs, I get the following message: "KS_X30_2018 v 1.13 requires unknown base mod to be installed. / KS_X30_2018 1.13".

I have tried verifying all rFactor files on Steam and everything else in rFactor seems to be ok, but I get this message every time that I start rFactor2 and the X30 Karts are missing.

Can anyone help me out in getting all components of KartSim installed properly?

Thanks!

 

Thanks for the link. However, I've tried all the suggestions in the thread (except unsubscribing/re-subscribing) and it didn't help.

How does one "unsubscribe/re-subscribe"? And What specific files should I unsubscribe and re-subscribe?

Thanks again!

 

Also, the thought occurred to me of uninstalling, then re-installing all of rFactor2. But I'm reluctant to go thru all that.

 

Whoa! I just re-started rF2 and everything is loaded now and working fine. I don't know what happened, but THANKS to who ever fixed it!