Missing colonist toolbar (probably mod-related)

[CruelBanana]

So, I tried installing a new mod and launched my permadeath colony (I know, bad idea). The colonist bat at the top is completely gone, the 4-square thing at the bottom is checked, and changing resolution didn't help. I deleted the mod entirely, but the game is still screw. I would be very grateful for help in this issue. Here is the debug mesage:
Argument is out of range.
Parameter name: index
  at System.Collections.Generic.List`1[System.Int32].get_Item (Int32 index) [0x00000] in <filename unknown>:0
  at RimWorld.ColonistBarDrawLocsFinder.CalculateColonistsInGroup () [0x00000] in <filename unknown>:0
  at RimWorld.ColonistBarDrawLocsFinder.CalculateDrawLocs (System.Collections.Generic.List`1 outDrawLocs, System.Single& scale) [0x00000] in <filename unknown>:0
  at RimWorld.ColonistBar.CheckRecacheEntries () [0x00000] in <filename unknown>:0
  at RimWorld.ColonistBar.get_Entries () [0x00000] in <filename unknown>:0
  at RimWorld.ColonistBar.ColonistBarOnGUI () [0x00000] in <filename unknown>:0
  at RimWorld.MapInterface.MapInterfaceOnGUI_BeforeMainTabs () [0x00000] in <filename unknown>:0
  at RimWorld.UIRoot_Play.UIRootOnGUI () [0x00000] in <filename unknown>:0
  at Verse.Root.OnGUI () [0x00000] in <filename unknown>:0

[CruelBanana]

After hours of dancing around this issue the bar reappeared after I merged the 2 caravans I had on the world map. Now I wonder how can that be an issue? Because I remember the bar was there when I sent those 2 caravans out, and everything was well. Does it indicate that I have some serious problem with my game or mods? And what should I, or everyone who can run across this issue, do in such cases?