Whilst attempting to upload a new blog article, using Windows Live Writer (build 14), recently I received the following warning “Invalid Server Response: The response to the metaWeblog.newMediaObject method receive from the blog service was invalid: Invalid response document returned from XmlRpc server” after which the upload aborted.

The curious thing was that other posts were uploading just fine. The error indicated an issue trying to create a media based object on the server and after taking the article apart I noticed the attached image in the blog article was just under 200 KB – which is larger than normal – I usually try and keep them to under 50 KB.

Sure enough, re-sampling the image down to 35 KB and replacing the image sent the problem away. I can only imagine the server must be timing out due to the large size of the file or perhaps the total size of the upload is hitting some upper threshold on the server.

A number of articles on the internet indicate that increasing the memory_limit field in the php.ini file on the server might also fix the problem – however I plan to keep it as it is for now as it’s a useful reminder to check the size of embedded images.