I was playing Endless Space 2 this afternoon and got stuck at the beginning of a fleet battle(RiftBorn vs. Sophons). It kept saying that my opponent, which is AI, is choosing their strategy. Then, I reload that round and choose not to engage(retreat) and it solves the problem. However, the same thing happened the next round, I got stuck again at the beginning of a ground battle, and I couldn't get around of it this time. Does anyone know how to solve this problem? Help pls~

Thanks

This happened to me also. 

Playing with UE using the beginner game tutorial setup.

At turn 86 was unable to progress past the fight notification, and therefor unable to end my turn.

Reloaded at previous turns but once I got back to the same turn count it happened again.

Unable to retreat, or view advanced tactics. Basically the fight window was broken.

v. 1.0.5

Same problem with me playing as the Sophons. I was on turn 143 and I tried to get into a space battle, the battle never started, with the tooltip saying that the AI is choosing its strategy. I reloaded the auto save and avoided the battle, but then when i tried to end my turn I have been hit with a never-ending "Pending" status. It also says that two of the AI empires, the Cravers and Horatio, are "In Encoun", which I presume means "in encounter". Seems like I am going to have to abandon this game unless there is some fix.

Same with the Traders, sucks, that's 2 games in a row....

If you guys could upload the applicable save/diagnostics files for  these problem, devs may be able to help in next patch.  Here's the bug report guidelines:

https://www.games2gether.com/endless-space-2/forums/114-bug-reports/threads/21380-the-tester-s-guide-to-the-bug-report

In particular:

8. Attachments

Don't forget to attach useful files if you feel like they are relevant.

• Screenshots (you can edit them to add a beautiful red circle made on MS Paint to help us identify the issue)
• Save files (be it manual saves or autosaves and don't worry we're not going to judge if you're playing Ecologist Cravers)
• Diagnostic  files (located by default under  "C:\Users\YOUR_USER_NAME\Documents\Endless Space 2\Temporary Files"  -then select the correct file by looking at the name like "Diagnostics - 2016'10'11 @1407'46''" that gives you the date and hour which should correspond to a save file)
• Dump files (located by default under _C:\Users\YOUR_USER_NAME\Documents\Endless Space 2\Dump Files_\ )
  Zip the folder named like _DesyncReport.001.d0538fe6-0de7-4f7b-a30e-4bcee38bbd45_ (the first three numbers are the turn the dump was made on, the rest is irrelevant)

Which is to say, in MP games, I've been encountering very laggy combat, tho none ultimately failed to resolve, they did suspend UI interactivity for the duration of the combat resolution, which meant until end turn.  May be a related issue to the one you're encountering.  Maybe I will be able to upload my own saves, but will probably put them on a separate thread.