Interesting...did it crash after researching a tech (if you remember)? I could see it crashing on auto-upgrade/autosave and getting confused on reload. Otherwise that's quite the head-scratcher   THanks for the save file, I'll give it a look!

Heh. This happened to me in Beta 1z2 ALOT. The game would freeze (usually upon hitting the end turn button) ... sometimes its very thoroughly frozen and I have to completely abandon the game. However, SOMETIMES it will loosen enough for me to save the game. Once I load the game (usually after exiting game first) almost ALL buildings will be "seen" as under construction, however for all intents and purposes they were actually built.

For buildings actually under construction at the time of the anomaly, they will still be successfully built and show as built upon completion as normal. Its only all the pre-existing structures that are indefinitely stuck in "under construction graphics" ... if I recall correctly, once you save such a game and re-load, the buildings will once again reappear as normal.

I found some instances where buildings that were completed would still be considered under construction because it was comparing the labor done on the building to the current labor needed to complete a building of that type to determine if it was "completed," instead of just checking if it had finished construction.  Because cities can increase/decrease the amount of time needed to complete a building through other buildings and abilities and stuff like that, this would cause some buildings to be considered under construction all of a sudden.  I've fixed this for the next update, though.  Hopefully this is the same thing you guys were seeing on load, it was just more apparent then because the improvement icons would be recreated to show the hammer in the corner, whereas it was probably failing those construction tests more silently before you saved.