[Here I Stand (500th Anniversary Edition)] NullPointerException: Cannot invoke "VASSAL.chat.node.SocketHandler.writeLine(String)" because "this.sender" is null

[uckelman]

ABR
Version	3.7.15
Reporter
Error Log	7708 bytes

lost connection to a game.
Then can't rejoin. got this error

Here I Stand (500th Anniversary Edition) v3.4 3.7.15

java.lang.NullPointerException: Cannot invoke "VASSAL.chat.node.SocketHandler.writeLine(String)" because "this.sender" is null
 at VASSAL.chat.node.NodeClient.send(NodeClient.java:243)
 at VASSAL.chat.node.NodeClient.forward(NodeClient.java:315)
 at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:323)
 at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:290)

[riverwanderer]

Possibly a common cause at VASSAL.build.GameModule.sendAndLog(GameModule.java:1864) ?

#13862: java.lang.NullPointerException: Cannot invoke "VASSAL.chat.node.SocketHandler.writeLine(String)" because "this.sender" is null
at VASSAL.chat.node.NodeClient.send(NodeClient.java:243)
at VASSAL.chat.node.NodeClient.forward(NodeClient.java:315)
at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:323)
at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:290)
at VASSAL.chat.HybridClient.sendToOthers(HybridClient.java:85)
at VASSAL.build.GameModule.sendAndLog(GameModule.java:1864)
at VASSAL.build.module.map.Flare.mousePressed(Flare.java:634)
at java.desktop/java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:288)
at VASSAL.build.module.Map.mousePressed(Map.java:1988)

#13666: java.lang.NullPointerException: Cannot invoke "VASSAL.chat.node.SocketHandler.writeLine(String)" because "this.sender" is null
at VASSAL.chat.node.NodeClient.send(NodeClient.java:243)
at VASSAL.chat.node.NodeClient.forward(NodeClient.java:315)
at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:323)
at VASSAL.chat.node.NodeClient.sendToOthers(NodeClient.java:290)
at VASSAL.chat.HybridClient.sendToOthers(HybridClient.java:85)
at VASSAL.build.GameModule.sendAndLog(GameModule.java:1864)
at VASSAL.build.module.PlayerRoster.finish(PlayerRoster.java:509)
at VASSAL.build.module.WizardSupport$GameSetupPanels.finish(WizardSupport.java:948)