So I already conquer Dir-Klou and advance to Necrosia, but when I already conquer Necrosia and want to progress, I stuck and cannot advance to Dir-Klou because they already has been conquered. I think this is a bug.
Viewing post in Shuggerlain (v0.73) comments
I had the same issue. To get round it I edited my save using https://www.saveeditonline.com/
Where it said "DK Story 2" I changed it to "DK Story 0" and it let me enter Dir-Klou and just redo the Dir-Klou part.