Hello, I am a Japanese mse user and thank for your developing.
Now I met a trouble that as the title says. I cannot type Japanese on mse. I can only paste Japanese text on it. At ver 2.0.0, I could type in Japanese. So, now I am typing my set with 2.0.0. and then editing with 2.1.2. It's a bit tough.
I would be appreciated if you make it allow Japanese typing on next update.
Generally, Japanese are very bad at English. So, they would rarely come this English community. I imagine it caused you to end supporting Japanese input. But that does not mean there's no demand for mse in Japan. Searching twitter for #MTGオリカ (means original cards), you'll find some users.
I cannot fluently write English. If you found more appropriate or cooler words for my card name, flavor text or post, I will be glad to hear your advice.
I don't believe this change was intended. There is a report for 2.1.2 that a user is unable to type Russian characters, but is able to paste them in. It sounds like this problem is affecting non-Roman character sets in some way.
I've added a comment here on your behalf, mentioning that the issue is affecting Japanese characters as well.