Looks like that's it - OSM is the problem. Switched to World Topo and no problems.
Thanks for the suggestion!
Thanks for flagging this up John. It looks like there may be a problem with the highly zoomed in OSM map tiles in your area, as the map tile requests are timing out. We'll look into it as soon as possible. For now, can you try printing the route over fewer pages, which would use lower zoom level map tiles, or select a different map type like the Paths map or thr World Topo map?
Update: Also getting the same error when trying to PRINT from Mobile, or an external machine connected by VPN.
Houston...it looks like we have a problem. :)
Receiving the print error for the last several hours:
We normally generate printouts in PDF format but the PDF print service is temporarily unavailable. Please try again in a few moments or click the following button to print the route using your web browser.
When trying to print from the web browser, the map layer is not displayed. See : https://photos.app.goo.gl/S1jfiwHjtoJ59Sdn7
Thanks for your help.