Problem connecting Celeste to FMOD Live Update, even after trying solutions from similar posts here

FMOD Studio
1

Hi everyone,

I’ve been following the instructions for connecting Celeste to the available FMOD Studio project, but I’m having issues getting the live update to work: https://www.fmod.com/docs/2.03/studio/appendix-a-celeste.html

I’m using FMOD version 1.10.10, and I have not made any changes to the FMOD project before building the banks.

I had the same issue as others on this forum, with the game initially not opening after rebuilding the banks as directed in the link above. I then managed to get the game to open again after changing the game version to 1.2.5.0 and re-building the banks, as suggested in this thread: Problem with celeste+fmod

image
image839×592 43.1 KB

However, connecting to Live Update is still not working. I get the following “Socket Error” message:

Screenshot 2026-09-04 143630
Screenshot 2026-09-04 143630543×175 6.04 KB

I also have these error logs coming up; I don’t know what to do with this information:

Monocle Engine Error Log

04/09/2026 15:39:54
System.Runtime.Serialization.SerializationException: The input stream is not a valid binary format. The starting contents (in bytes) are: 3C-3F-78-6D-6C-20-76-65-72-73-69-6F-6E-3D-22-31-2E ...
at System.Runtime.Serialization.Formatters.Binary.SerializationHeaderRecord.Read(__BinaryParser input)
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadSerializationHeaderRecord()
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at Celeste.UserIO.Deserialize[T](Stream stream)
at Celeste.UserIO.Load[T](String path, Boolean backup)

04/09/2026 14:35:39
System.Runtime.Serialization.SerializationException: The input stream is not a valid binary format. The starting contents (in bytes) are: 3C-3F-78-6D-6C-20-76-65-72-73-69-6F-6E-3D-22-31-2E ...
at System.Runtime.Serialization.Formatters.Binary.SerializationHeaderRecord.Read(__BinaryParser input)
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadSerializationHeaderRecord()
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream)
at Celeste.UserIO.Deserialize[T](Stream stream)
at Celeste.UserIO.Load[T](String path, Boolean backup)

04/09/2026 14:28:21
System.Runtime.Serialization.SerializationException: The input stream is not a valid binary format. The starting contents (in bytes) are: 3C-3F-78-6D-6C-20-76-65-72-73-69-6F-6E-3D-22-31-2E ...
at System.Runtime.Serialization.Formatters.Binary.SerializationHeaderRecord.Read(__BinaryParser input)
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadSerializationHeaderRecord()
at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream)
at Celeste.UserIO.Deserialize[T](Stream stream)
at Celeste.UserIO.Load[T](String path, Boolean backup)

Any help would be much appreciated!

Thanks in advance,
Anni