To explain:

1. Was playing, and had 2 cities, plus 2 outposts. 1 city and outpost got conquered, and then after a white peace was struck.

2. Lone archer group far off from my other cities (barbarians in between) started settling another outpost.

3. Second city I for testing purposes gave away in a peace treaty with another AI. The outpost timer on the lone outpost timer had 3 turns left on it.

4. The game urges me to turn the unfinished outpost into a city before I can go to the next turn.

5. Because the outpost is unfinished, I cannot setup new production in it to turn it into a city. Making me unable to go next turn.

As a side note, I ran the game through Proton. Can say it works entirely fine for proton users on linux, no hitches, no glitches. Will wait with writing a protonDB report until the game is released.

Similar thing happens when you relocate an outpost and then change from nomad into first era. Game tells you that turn can't be finished. Had to cancel the relocation, finish the turn and then start the relocation again.

anton95_rct wrote:

Similar thing happens when you relocate an outpost and then change from nomad into first era. Game tells you that turn can't be finished. Had to cancel the relocation, finish the turn and then start the relocation again.

the issues very likely have overlap or a common cause

Have the same issue. Had an outpost, moved into ancient era, couldn't end turn as city or outpost has no construction. Tried relocate, still wouldn't let me end turn with the same message. 

So basically I am now forced to create my city at that same outpost area and set a construction before I can proceed. 

Also - maybe related, maybe not - one game I had settled two outposts before turning one into a city, and the game stuck saying an outpost was idle (or something similar) when in fact the outpost hadn't even finished building.

Also also, there seems to be some kind of bugginess with the turns-to-complete timers when building outposts at the beginning of the game: the HUD will show 1 turn to complete when founding the outpost. After ending that turn and it will still show 1 turn to complete.  After completing the second turn it will complete.