Why is the flee market not available?

well from looking through the server log, the first error that comes up is because Ereshkigals all in one mod is configured improperly. Try reinstalling the mod with minimal if any changes to the config to see if that is what is causing your problems.

also what other mods are you running as improper configuration could result in errors.

Flea is still fragile at the momemt IMO.

Judging from you server log it seems you are running a old server, possibly pre-1.0 release because I don't see the startup banner in your log. Please update the server, move VeryGery's mod out and see if there's any improvement.

BTW you have disableragfair enabled in senko-aio, I wonder how you get into the flea market...

Try starting the server and open the game without any mods loaded. If the flee market is still bugged out then it is the Aki install. If the market is fixed without the mods then one by one add back the mods and start the server to single out which one is causing the problem.