remove paranoia code after fix for #69128

src/vs/workbench/api/electron-browser/mainThreadDebugService.ts

@@ -36,11 +36,7 @@ export class MainThreadDebugService implements MainThreadDebugServiceShape, IDeb
 		this._proxy = extHostContext.getProxy(ExtHostContext.ExtHostDebugService);
 		this._toDispose = [];
 		this._toDispose.push(debugService.onDidNewSession(session => {
-			if (session) {
-				this._proxy.$acceptDebugSessionStarted(this.getSessionDto(session));
-			} else {
-				console.error('undefined session received in onDidNewSession');
-			}
+			this._proxy.$acceptDebugSessionStarted(this.getSessionDto(session));
 		}));
 		// Need to start listening early to new session events because a custom event can come while a session is initialising
 		this._toDispose.push(debugService.onWillNewSession(session => {

src/vs/workbench/api/node/extHostDebugService.ts

@@ -601,11 +601,7 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 
 	public async $acceptDebugSessionStarted(sessionDto: IDebugSessionDto): Promise<void> {
 		const session = await this.getSession(sessionDto);
-		if (session) {
-			this._onDidStartDebugSession.fire(session);
-		} else {
-			console.error('undefined session received in acceptDebugSessionStarted');	// should not happen (but see #69128)
-		}
+		this._onDidStartDebugSession.fire(session);
 	}
 
 	public async $acceptDebugSessionTerminated(sessionDto: IDebugSessionDto): Promise<void> {