I'm getting this error even in vanilla client after the server transfer.
java.lang.RuntimeException: could not load extension:
https://game.havenandhearth.com/java/launcher-ext.jar at haven.launcher.Config.command(Config.java:337)
at haven.launcher.Config.read(Config.java:373)
at haven.launcher.Driver.main(Driver.java:153)
Caused by: java.net.ConnectException: Connection refused: no further information
at java.base/sun.nio.ch.Net.pollConnect(Native Method)
at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:660)
at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:549)
at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:597)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:333)
at java.base/java.net.Socket.connect(Socket.java:648)
at java.base/sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:290)
at java.base/sun.net.NetworkClient.doConnect(NetworkClient.java:177)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:474)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:569)
at java.base/sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:265)
at java.base/sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:372)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:189)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1194)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1082)
at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:175)
at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:142)
at haven.launcher.Cache.update0(Cache.java:275)
at haven.launcher.Cache.update(Cache.java:360)
at haven.launcher.Resource.update(Resource.java:75)
at haven.launcher.Extension.load(Extension.java:47)
at haven.launcher.Config.command(Config.java:334)
... 2 more
Suppressed: java.net.ConnectException: Connection refused: no further information
... 24 more
Suppressed: java.net.ConnectException: Connection refused: no further information
... 24 more