If mudfish is failed with Mudfish failed to execute error message, please try to one of the following workarounds:

• If you're using v4.6.1, please log out and log in at the mudfish launcher, (check https://imgur.com/a/ZZJEwy0 image). This issue is mostly related with auto-login feature of Mudfish. So this issue could happen if auto-login is enabled.
• Or please downgrade to mudfish v4.5.5 found at https://mudfish.net/releases/ link.

Sorry for this inconvenience. :-( It seems this is a bug of latest mudfish when new month is started.