fix(core): Give better error message if executions.process is still used in the configs (#8618)

packages/cli/src/config/index.ts

@@ -73,6 +73,11 @@ if (userManagement.jwtRefreshTimeoutHours >= userManagement.jwtSessionDurationHo
 
 	config.set('userManagement.jwtRefreshTimeoutHours', 0);
 }
+if (config.getEnv('executions.process') !== 'IGNORED') {
+	throw new ApplicationError(
+		'Own mode has been removed. If you need the isolation and performance gains, please consider using queue mode.',
+	);
+}
 
 setGlobalState({
 	defaultTimezone: config.getEnv('generic.timezone'),

packages/cli/src/config/schema.ts

@@ -234,6 +234,14 @@ export const schema = {
 	},
 
 	executions: {
+		// By default workflows get always executed in the main process.
+		// TODO: remove this and all usage of `executions.process` when we're sure that nobody has this in their config file anymore.
+		process: {
+			doc: 'Own mode has been removed and is only here for backwards compatibility of config files. N8n will use main mode for executions unless `executions.mode` is set to `queue`.',
+			format: ['main', 'own', 'IGNORED'] as const,
+			default: 'IGNORED',
+			env: 'EXECUTIONS_PROCESS',
+		},
 		mode: {
 			doc: 'If it should run executions directly or via queue',
 			format: ['regular', 'queue'] as const,