Hi Stephanie, that folder is associated with Google Drive rather than OneDrive, It is a
cache of Backup and Sync for Google Drive . . .

It is a known issue, please read the article below:

https://productforums.google.com/forum/#!topic/...

Hi StephanieBernhagen,

Sorry for the inconvenience caused to you, and thank you for your valuable question please, This folder is associated with Google Drive, It is temporary folder which is created each time when you download any thing from Google Drive, It is OK to delete it, no worries please.

Please let me know, if that helps and feel free to ask back any question.

Kind Regards:
Yasir

Thank you. I tried to find the files mentioned in the article with no luck. I'm still stuck. 

Hi Stephanie, do you use Google Drive on your System?

According to Google Support:

This folder is a hidden folder that appears at the root of your Google Drive folder as a temporary download space for new items that need to be synced and moved into place. Please do not delete this folder or syncing will be broken. It is an improvement over using %TEMP% space as the latter does not work well when it is on a different partition than your Google Drive folder resides.

https://productforums.google.com/forum/#!topic/...

Well, isn't this a catch 22? I have just installed Google Drive to upload some of my pictures and it fails the upload immediately because it can't upload ".tmp.drivedownload" !!!

Hi,

Situation: Both OneDrive and Google Backup/Sync are running at the same time, and both are working in my Documents folder.

Still a OneDrive issue! Here's why:

1. OneDrive LOCKS this .tmp.drivedownload folder and its contents for uploading, and thus prevents Google Sync from working in it properly. Race condition!
2. OneDrive syncs this folder and its temporary contents to Microsoft, thus even after Google Sync is done with it and tries to delete it, OneDrive RESTORES the deleted folder and contents occasionally. (Happens if I don't let Google Sync finish - especially during Sleep/Hibernation/Power loss conditions.)
3. Google Sync MOVES my actual files files into and out of this temp folder, so OneDrive THINKS the user DELETED the current file being synced. And promptly deletes it from OneDrive. (They also get renamed by Google Sync to *.tmp which further confuses OneDrive.)
4. Then Google Sync moves the file back a few seconds later, and OneDrive reuploads the temporarily moved file again. Wasting double my bandwidth and creating useless file modifications history and filling my trash with duplicates.
5. Google Sync cannot work if there already is a temp folder. (Wrong attributes too; Not system and Not hidden) OneDrive interrupts Google Sync by keeping the tmp folder around. I have to manually delete it, frequently. With files inside! Who knows if some of my data is LOST then, or not?
6. Google Sync is guilty too, of not using TMP anymore (It used to, in the past...) At least when both TMP and GD are on C:\, it SHOULD!
7. OneDrive spams randomly named GUID files in the root folder, such as ".2339C9593-DI756-4EC6-8DE-4241E2A707B" and even after I delete them it recreates them. Keep it elsewhere, damn it! Google Sync uploads and tracks changes to this stupid OneDrive-exclusive settings file. And then OneDrive gets confused when Google Sync changes the GUID back during an "out of sync" Sync.
8. There are inadequate settings in OneDrive. We can't blacklist the folder, to prevent it from being OneDrive'd.
9. Google Sync can blacklist file extensions, but not file names, and since the GUID spam has random file extensions and HAS NO NAME, I cannot prevent Google Sync from uploading OneDrive's junk file either.
10. This is insufficient. One is similar to the other in ineptitude. Like how I can't blacklist Google Sync folders in OneDrive. Both have insufficient settings.

Race conditions and interference all around. Both are at fault for not ignoring each other and for working / being designed in various stupid ways that aren't compatible with one another.

Workaround is terrible: Run OneDrive first, wait for it to sync, then KILL OneDrive. Only THEN may one run Google Sync, also wait for it to finish, and KILL that too. The two cannot run at the same time.

Antivirus companies fixed this years ago. Cloud apps should, too.

Solution:

1. OneDrive: Give the GUID file a NAME! So I can blacklist it.
2. Google Sync: Stop spamming tmp folders! Keep it in %TMP% like you're supposed to. If and only if both TMP and the folder being synced is on the same drive (C:\ 99% of the time. Stop catering to the 1% this way. Prioritize the 99%'s convenience!)
3. Both OneDrive and Google Sync: PROPER ability to Blacklist FOLDERS as well as files, based on regex pattern matching.
4. DETECT it the competitor's software is running and stay the hell out of each others way!
5. Be polite. Don't be evil. Do the right thing. Where do you want to go today? Empowering us all. Your potential. Our passion. Be what's next.
6. EEE!

Sent to both Microsoft and Google. http://forum.3ice.hu/viewtopic.php?f=15&t=975&p=5394#p5394

Sincerely,

Daniel "3ICE" Berezvai

3ice.hu

Edit: Links made clickable. This is no GMail, apparently. One must manually format their links even if they're fully qualified with protocol (http://)