Issue has persisted with 9.1.1 #03 mod pack. Removing Roslich's Side Panels and Custom Battle Loading Screen mods allows the game to start as normal. Note, I am not using a Steam version of the WoWS client.
I have attached markup.xml and USSExpressionsLoader.xml again but this time with the non-working mods installed
markup.xml
USSExpressionsLoader.xml
Just for kicks, here's another copy of the XML files after running the game with the non-working mods uninstalled
markup.xml
USSExpressionsLoader.xml