EDIT, in case anyone finds this thread in a search: it seems like the problem was definitely on Apple's end, and after a few days they were able to fix it. I went two days with no access to iCloud drive, and then two more with sporadic and unreliable access. At this point it's now been 5 days since iCloud drive can back online for me fully, and (*knock on wood*) it now seems fine. My advice to others who encounter the problems described below: 1) if you can't access icloud drive through icloud.com (and you get error messages to that effect), then your only real options are A) to wait, or B) to call apple. There's nothing you can do on your end to fix it. 2) If possible, do not turn off iCloud drive on your Mac. This will move all your files to an "iCloud Drive (archive)" folder, and when the system comes back online you'll have to re-download everything. In my experience, turning off iCloud drive did not help fix anything. I will note, however, that turning of iCloud drive on my iPad was required if I wanted to use Pages or Numbers on the iPad (none of the iCloud drive documents were accessible). ----ORIGINAL POST and thread below––––– I'm a long (long) longtime Mac user and heavy iCloud drive user. I have hundreds of PDF files and Pages files that I work on every day on both my iPad (Pro 12.9) and my Mac (2014 Mini). It's been working great for a very long time. This morning iCloud drive was not uploading any files I modified on my Mac. I started troubleshooting and realized nothing was going up or down to the cloud. My internet connection was fine. Then, when going to iCloud.com, logging in, and choosing iCloud dirve, I get a message that says "Can't load iCloud Drive." If I go to Pages on icloud.com I can see my documents, but trying to open one gives the error "Sorry, something went wrong." I turned iCloud Drive off and then back on on my iPad, but now that just means that the iCloud drive app is blank (there should be thosuands of fiesl – about 70GB of data – there), and if I lanch Pages on the iPad it just spins looking for documents. I took the very rare step of calling apple, spending the needed 40 minutes to get escalated to a supervisor. They gathered a bunch of data from my Mac, which seems like a waste to me since the error is clearly on the server side. I can log into a brand new Mac and go to icloud.com and it says "Can't load iCloud drive" and my iPad can't see any of my icloud drive data, so it has nothing to do with my Mac. I'm completely backed up, but not sure what step to take next. At the moment, I can't use my iPad at all (no access to any documents). I'm *heavily* dependent on iCloud drive because my primary work flow is working on dozens of PDFs in PDF Expert and dozens of Pages documents in Pages, and I move back and forth between my Mac and iPad all the time. ANY THOUGHTS? For the record: the Mini is running the newest version of MacOS Sierra, and the iPad is running iOS 10.2.1. The Mini has 120GB free on its SSD, and the iPad has 10GB of storage free. I run basically NO third party software other than – 1Password, Dropbox, MS Word. My home network is working fine, with 25MB upload and low latency. My wife is running a Mac and an iPad in the same house, and her iCloud drive is working fine. Yesterday afternoon this was working OK for me; the problem began this morning when I noticed while on my Mac that none of the documents I'd created/updated this morning were uploading to iCloud drive. UPDATE: I just went to icloud.com and just tried to download one of my Pages documents; it gave me the error "due to account maintenance, Pages is locked." Some message in Numbers. Not sure if this means they are actually working on it, or it's just the error message it's spitting out.