OneNote Mobile for iPhone - RE: "Login failed, error: 400" Error

OneNote Mobile for iPhone - RE: "Login failed, error: 400" Error

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First of all thank you very much for your interest in OneNote Mobile for the iPhone, there has been a tremendous response thus far.

We have received reports from customers who are hitting an error on initial login, with the following message: "Login failed, error: 400".


The team has been investigating the issue and believe we have identified the cause. We are working on an update. However the underlying cause is an intermittent issue, due to overwhelming interest in the app. The workaround is to keep trying to sign in, once you get past this error then OneNote will sync without any problem.

Thank you for your patience and interest in OneNote, we all apologize for the inconvenience.

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  • I would love to see OneNote for the Android Platform.  I love OneNote and it's only gotten better with each iteration.

    But I don't have an iPhone and don't see myself getting one for at least another two years (hmm - why would that be... <G>).

  • After about a day of trying (error 400), it finally worked!!!

  • I tried is few times and received the same error.  The following morning i tried again, and on the 3rd attempt it worked.  Thank you.

  • I have found that I can't log in when using WiFi but can if I turn off WiFi and use 3G.

  • I used Thom_D earlier suggestion of trying to rapidly log in, and after a few tries it worked! Prior to this I had powered off my Touch, based on another suggestion. Dunno if the power off was necessary, but I'm finally in.

    But my dilemma: I use a Touch, not an iPhone. I don't always have internet connectivity. It occurred to me that I might not be able to get to my OneNote files if I'm not online. If that's the case, it's truly a bummer and the app is useless to me.

  • Now that I can login, finally, I get the notebook syncing error, "Loading list of notebooks failed. (501)"  Manually trying to sync, I get error codes 400, 401, 500 and 501 randomly.

    The whole notion of "after you login it will work" is simply not true.

  • Well, thanks to the update I no longer get the 400 error. Now I get one that says "login failed, error 2147186438"

  • When click install on my iPhone, a popup box appears asking me to log on to itunes when I type in my password it

    Loops back to install screen to click install again then the popup appears again and it never installs it just keep going around in a loop? What's the problem?

  • Error 405 for days now. Really?  Come on MS, fix this please.

  • Version 1.3 still have error 400. Any news? Thanks

  • I also still have this error in the iPad version. Any help?

  • If people are still having the 400 error please email me and on the contact link and then we can work over email to try and figure out what is going on.

  • I can access the application on my PC. I can access my skydrive. I have attempted many of the solutions put forth on various forums.

    I cannot access it from either of my apple devices for weeks.

  • Brian - Sorry to hear this, if you are still having problems would you please email us at the link on the top of this page?  Then we can help look into this further.  

  • The app worked great on my iPhone for a few days - just long enough to get me to migrate all my notebooks over from Evernote.  Now I'm getting the 405 "can't sync" error.  

    It's a real shame, as I prefer the OneNote organizing system to Evernote, but if I can't use it from my phone, it's pretty much useless to me.

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