dorbian
This is correct.
We have a number of checks:
1) Dalamud plugin requires a certain server version (breaking change)
2) Server requires a certain dalamud plugin version (non-breaking change) -> "There is an update, please update your plugin"
3) Server requires a certain dalamud plugin version (breaking change) -> "You cannot connect unless you update your plugin".
What you experienced yesterday was a breaking change on the dev branch that is not yet released to the main branch. Hence always connect to main :D.