Equestria at War has received its 1.9 update. However, it requires not 1.9.0 but 1.9.1 [beta].

Anyone still rolled back to 1.8 will have their game crash, and just reverting to 1.9.0 won't be enough. Opt into 1.9.1 [beta] the same way you rolled back to 1.8.1. In addition, disabling all submods which have not yet been updated is highly recommended, as most will overwrite the new mod files with old version. Do so and we can all enjoy ponies and war again.

Don't forget to thank the Devs! Thank you!

P.S. Spoiler: There are now HUMANS in the mod, southeast corner of Equestria!!! Whoo!