Some have been poking me to put this under a release since the author of Harmony has not released the fixed .Net 9 DLL, so here you go. A PR was made and accepted by the repository owner as seen in (pardeike#637). It is a matter of time before a release for a fixed version of Harmony under .Net 9 is made. Until then, I hope this helps out.
Once Harmony releases the .Net 9 version, I will delete this release.
SHA256
0Harmony.dll - 6D0A6A612B04A8C1D54F47FB34E28334CBDB594F5D263C3C5160F4384D16E9B4