**Misleading "Codec type is not registered" error for RemoteAttachment**

[mchenani]

Summary

When sending a message, users receive a confusing error message stating "Codec type is not registered" even when both and are properly registered. The actual issue is that the object is missing required properties ( and ). RemoteAttachment``RemoteAttachmentCodec``AttachmentCodec``RemoteAttachment``contentLength``filename

Current Behavior

• Error message: "Codec type is not registered"
• Users assume the codec registration is the problem
• The actual cause (missing required properties) is not communicated

Expected Behavior

• Clear, specific error message indicating which required properties are missing
• Error message should help developers understand the actual problem

Root Cause

The issue occurs when a is created without setting the required and properties. The codec fails during encoding/decoding, but the error handling incorrectly reports this as a codec registration issue rather than a validation/encoding failure. RemoteAttachment``contentLength``filename

Workaround

Ensure all required properties are set before sending:

val remoteAttachment = RemoteAttachment.from(
    encryptedEncodedContent = contents[0].second,
    url = URL(contents[0].first.assetUrl),
)
remoteAttachment.contentLength = attachment.data.size()
remoteAttachment.filename = attachment.filename

Proposed Solution

1. Improve error handling: Catch codec encoding failures and provide more specific error messages
2. Add validation: Validate properties before attempting to encode RemoteAttachment
3. Better error messages: Replace generic "Codec type is not registered" with specific validation errors