Fix assertion when modules are accessed early on in bridge startup

React/Base/RCTBatchedBridge.m

@@ -407,9 +407,10 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
 
 - (NSDictionary *)modules
 {
-  RCTAssert(!self.isValid || _modulesByName != nil, @"Bridge modules have not yet been initialized. "
-            "You may be trying to access a module too early in the startup procedure.");
-
+  if (RCT_DEBUG && self.isValid && _modulesByName == nil) {
+    RCTLogError(@"Bridge modules have not yet been initialized. You may be "
+                "trying to access a module too early in the startup procedure.");
+  }
   return _modulesByName;
 }
 

React/Base/RCTLog.m

@@ -226,7 +226,11 @@ void _RCTLogFormat(
           }
         }
       }];
-      [[RCTBridge currentBridge].redBox showErrorMessage:message withStack:stack];
+      dispatch_async(dispatch_get_main_queue(), ^{
+        // red box is thread safe, but by deferring to main queue we avoid a startup
+        // race condition that causes the module to be accessed before it has loaded
+        [[RCTBridge currentBridge].redBox showErrorMessage:message withStack:stack];
+      });
     }
 
     // Log to JS executor