Here I will now list the errors concerning most ciwylization:
1.AI does not benefit from improvements available after building Forts
2.AI does not use the upgrades available in the capitol among others such as:
*.improvements for the explorer
*.upgrades for natives to achieve Legendary status
3.AI does not use upgrade available at trade factories to make trade happen by train
Now I will list the AI errors in each country that I noticed.:
4.Portuguese: AI does not use from the upgrade for the unit (organ/rabauld) to achieve the status of imperial rabauld.
5.Italians: AI does not use troops available in Basilica
6.Italians: after the newer update, the AI does not use upgrades for a unit (Pavisier) to reach Guardsman and Imperial status.
7.Ethiopia and Hausa (what I write is just my subjective opinion and that something can be improved from this angle): AI sells all cattle which does not give them the ability to produce a large amount (Influence)
which, as a consequence, AI can’t afford to quickly buy upgrades and troops that cost using (influence).
At this point I have listed all those bugs that were most noticeable to me during a few hours of battles with AI, of course there are more bugs or things to fix, but the ones I have listed above I think that for the very beginning it will be enough if they fix it.