I am having this issue with RealChute's icon on toolbar also. 1. On initial load at Space Center, I have 5 MOD buttons on toolbar (plus 2 stock buttons): ScanSAT, KCT, TWP, KAC, RC || contracts, messages (stock) 2. Leave Space Center to another building (such as Tracking Center or VAB), then return to Space Center. Toolbar is the same: 5 MOD buttons, plus 2 stock. 3. Leave Space Center to a vessel, then return to Space Center. Now the toolbar has only 4 MOD buttons, plus 2 stock: ScanSAT, TWP, KAC, KCT || contracts, messages (stock) ScanSAT = ScanSAT map icon (v12) TWP = Transfer Window Planner icon (v1.3.1) KAC = Kerbal Alarm Clock icon (v3.3.1.1) KCT = Kerbal Construction Time (v1.1.6) RC = RealChute icon (v1.3.2.3) (not full list of mods) should have some time tomorrow to get minimal list of MODs required to reproduce.