I'm doing historical missions, the "Investigate rock arches on the Mun" mission.
I've reached the Arch, taken samples, EVA, Crew reported, landed really near it (<100m), climbed it's top + crew report + Samples.. and still the contract is not satisfied.
What am I missing?
UPDATE
I think it's a bug. I've been there a second time, still nothing happens.
Screenshot added: 
2 Answers
Have you visited all the arches on the Mun? The easter egg KSP wiki page says:
Three giant rock arches can be found at 12° 27′ 2″ N 39° 11′ 45″ E, 12° 28′ 18″ S 140° 57′ 40″ W, and 2° 27′ 47″ N 81° 31′ 51″ E.
You have only explored one arch. If you find the others and explore them, you should complete the contract. 1
Maybe you have to return the sample back to Kerbin?
Otherwise, I would check the contract again in the Mission Control building at KSC. The description of the contract there might be more specific than the UI tooltip.
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