Hey there, thanks a million for flagging this! I really appreciate you taking the time to report it.
I just did a quick test run myself, downloading the game directly from the itch.io page (https://unirion.itch.io/waifu-elements#download), and it seems to be working smoothly on that front. Regarding the itch.io update client, you've hit on something interesting! I suspect the issue might be tied to how the client handles .exe file name changes between updates – something I'll be sure to iron out in the next patch to prevent this hiccup. My apologies for that snag!
For now, the best workaround is to grab the latest version manually from the download page: https://unirion.itch.io/waifu-elements#download. Just unzip and run, and you'll be back to summoning those waifus!
As a token of my gratitude for helping improve Waifu Elements experience, please send me a pm on Patreon (https://patreon.com/unirion) with your in-game UserID (you'll find it in the top right corner). I'll gladly credit your account with some extra tickets.
Thanks!
UPDATE: For some reasons, I forgot to mark my last update package as for windows. Have been fixed! Now it's seems to be downloadable with an itch app. Thanks again!