I had to reset the user Keychain on one of my Macs. Now DEVONthink Pro won’t sync. I get a
error for each database.
Seems a restore of the right entries from the old keychain would fix this. Any ideas on the right way to do this?
I’m very much hoping the official response isn’t to just start over. It takes a very long time to get Dropbox sync going on two machines with the size of my data and the speed of my uplink.
You might need to restart DEVONthink.
Tried that. Even rebooted.
This error is a little problematic because it seems to happen randomly. I’d started to assume it was my fault, which is why I advised you to restart DEVONthink.
Basically, this error happens sometimes, and goes away after a while. I’ve looked through the code a few times (basically, every time it’s reported, which is about once every two months or so), and can’t figure out anything that I (or my predecessor, who actually wrote the relevant code) did wrong. In fact, if the value for the oauth_token parameter weren’t supplied, DEVONthink would crash instead of encountering this error.
But nevertheless, whenever I encounter difficulty, I tend to suspect that it’s due to my own stupidity 
and I’m usually right.
The other possibility is that it’s an issue with Dropbox’s side. It’s a bit surprising, given the size and general success of Dropbox, but we’ve had occasional issues reported that turned out to be on their side.
The one thing that I do know for certain is that it’s temporary – so I’d suggest waiting a little while longer and retrying. I’d love to give you more information, or a more decisive way to resolve the issue, but I know next to nothing about Dropbox’s system, have not had good results with their support staff (whether user-level or developer-level), and, again, as far as I can tell Sync 1 is working as designed.
So no information pertinent to DT/Dropbox sync is stored in the keychain?
I have one machine syncing fine, and the other fails. Both worked fine prior to resetting the keychain on the one that now fails.
I can attempt to sync them sequentially, one after the other, and the state holds. One fails, one works. What kind of Dropbox issue affects one machine and not another at very close to the same time? A Dropbox issue that only affects DT sync, and no other Dropbox function? The only thing that’s changed since it last worked is one machine had the keychain reset. Without knowing the under the hood specifics, it’s hard to say it’s ONLY a Dropbox issue given the facts.
There is – but this information is inserted in the normal course of authentication/reauthentication. They’re called “OAuth Token” and “OAuth Token Secret”, which I guess were placeholders that made it into production 
You might need to explicitly reauthenticate with Dropbox (select the Dropbox location in Sync Preferences, click the “action” (gear) button below the location list, and click “Edit Location…”).
It’s a little more complicated than that – if you use the web interface, you’ll find a list of your authorized devices, which should include the device you’re using currently. As you know, Sync never uses or even sees your actual username and password, but rather is given temporary and revocable limited access to your account by Dropbox. If there is an issue with this mechanism – and OAuth is infamously a rather byzantine and problematic system – we might expect it to appear on some devices and not others.
Thanks for your patience, Nathan. Re-authenticating Dropbox seems to have fixed the issue. I was uncertain if that would affect the data store in any undesirable way. Your recommendation gave me license to give it a go.
Ah, I’m sorry for the wasted time. I should’ve suggested it sooner.