All this information are based on the sim version 188.8.131.52
No arrival procedures (STARs) available/selectable but included in the charts
A runway is missing or a runway-ident is wrong comparing the real-world and the default/stock scenery.
If this is the case, than the simulator can´t assigned a possible existing real-world STAR to this missing runway and therefore, the simulator disabled all available STARs.
Example (can be corrected due some sim-updates)
ZUUU - wrong runway-idents in the default scenery (2/20 instead of 02L/20R)
YBBN - missing runways in the default scenery (01L/19R missing, 14/32 not existing in real-world anylonger)
Report the missing runway/wrong runway-ident to ASOBO/MS or install (if available) any 3rd party addon-scenery, which includes the missing runways and/or correct the runway-idents. No navdata update necessary because the STARs are still included.