Links sent or received via iMessage using the BlueBubbles connector sometimes generate an attachment (see attached file) that contains the following message:

{"status":500,"message":"The server has encountered an error","error":{"type":"Server Error","message":"Attachment does not exist in disk!"}}

Note, that I added the .txt file extension so I could upload it.

42359206-E37B-4F29-8A48-2AF37E48522D.pluginPayloadAttachment.txt