See this link Error 44: Trouble uploading prototype (sharing upload error) – Adobe XD Feedback : Feature Requests & Bugs for the latest updates on this bug, and the actions you can take to help the team resolve this issue. There are also a couple of workaround solutions mentioned by the team that you can try.
it seems that you are trying to upload more data than your network connection can handle without causing a timing out of our services. We are working on some fixes that we hope to release soon. In the meant time: could you try to upload just about 10 artboards at a time? You can first just share and create a new link and then use the update button, that way you should end up with your complete prototype and it would reduce the data that needs to be uploaded significantly.
This is definitley not ideal but might give you the chance to create a complete prototype.