Error Marshall Overflow 603 (0x25B): Fix it With 4 Steps

ERROR_MARSHALL_OVERFLOW is a developer error, and it comes with 603 (0x25B) The user/kernel marshalling buffer has overflowed message. This error will cause problems with your code, but you can fix it with our solutions.

How can I fix ERROR_MARSHALL_OVERFLOW?

1. Update Windows, drivers and software

1. Check if Windows is up to date and ensure you have the latest updates installed.
2. Do the same for the software that is giving you this error.
3. Update your drivers.

For more information, visit our guide on how to update drivers on Windows 11.

2. Check the system logs

1. Press the Windows key + X and choose Event Viewer.
   
2. Next, navigate to Windows Logs and choose Application or System.
   
3. Look for errors or warnings that occurred around the game the issue appeared.
4. Analyze them and use this information to research the issue further.

3. Increase the buffer size

1. Check your code and increase the buffer size in the location where the marshalling happens.
2. If needed, allocate a larger buffer or handle data in smaller chunks.
3. If using RPC, verify the registry keys. To do that, press the Windows key + R and type regedit.
   
4. Next, go to HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc
5. Locate MaxRpcSize or its counterpart value and modify it if needed.

4. Other tips to try

1. Validate the size of data inputs before marshalling.
2. Split the data into smaller pieces if needed.
3. Try reproducing the issue on a different system.
4. Run the application with admin privileges.

These are just some of the tips you can use if you ever encounter ERROR_MARSHALL_OVERFLOW on your PC. In most cases, buffer adjustment will be necessary, but other solutions can work as well.

This isn’t the only overflow issue, and we already wrote about ERROR_STACK_OVERFLOW_READ and RESERVE_QUEUE_OVERFLOW in our previous guides.

We also have a guide on ERROR_BAD_COMPRESSION_BUFFER that we wrote recently, so don’t miss it for more information.