Same issue with PC (web) and iphone app, and with different internet services:
Error 504 Ray ID: 48e592c34ec3ab8a • 2018-12-24 19:47:19 UTC
Gateway time-out
I followed these instructions so I have an OPML to post sometime.
The surest way to prevent data loss in this case is to hover over the document title of the document that you’ve worked on, click on the menu icon, and choose “Export…”. Then, choose the “Download OPML file” option, which preserves all Dynalist attributes like checked states and color labels.
Meanwhile, I tried reloading, and I am now stuck without an app. No point using the iphone app because it doesn’t have the data which I saved to my PC.