The error 'Parse Error: Invalid character in chunk size' occurs becau…

…se both response.content_length and 'Transfer-Encoding': 'chunked' are being set in the server response. This creates a conflict, as Transfer-Encoding: chunked does not require a Content-Length. By removing response.content_length = len(image_data), this conflict is avoided, and the error is resolved.

navigator/actions/zammad.py

@@ -441,7 +441,6 @@ async def get_attachment_img(self, attachment: str, request: Request):
                     'Expires': expiring_date.strftime('%a, %d %b %Y %H:%M:%S GMT'),
                 }
             )
-            response.content_length = len(image_data)
             await response.prepare(request)
             await response.write(image_data)
             await response.write_eof()