The issue is resolved in gpg4win-5.0.0-beta479 @ win11:

• no error for opening .eml files
• no error for starting kleopatra while running (also not started twice anymore)

Thanks. Could you please clarify if the even-numbered minor version (2.2.x, 2.4.x, 2.6.x, etc) rule is still required? I'd like to provide clarity to the Homebrew team avoid any potential ambiguity

No it is not related to T4030 because that has not yet been implemented. I am just upload a beta479 which should fix problem as wel as other similar problems.

this also happens, when kleopatra is started while already running

Please use the the swdb.lst which has all the version info. The website is actually build using this info. Well, except for the README file in the FTP section. I will update that too.

Note that "Save encrypted" is only "Save" in the UI.

maybe related: T4030: GpgEX: Use process calls instead of UIServer protocol

new export option keep-expired?