Common sync issues and fixes in Proton Drive for Windows

Here are some of the most common issues you might have when syncing files from your Windows device with the Proton Drive app, along with steps to resolve them.

A quick note on sync speed: Because Proton Drive applies end-to-end encryption, every file and folder is encrypted individually before it’s uploaded. As a result, syncing a large number of small files or deeply nested folders can take significantly longer than syncing a single large file of the same total size.

If sync is slow but the Activity tab shows it’s still making progress, give it time rather than pausing, especially if you’re handling very large files — pausing cancels any current transfers and resuming starts them over.

Check for Proton Drive app updates

Most sync problems we are fixed by running the latest build of the Proton Drive Windows app. Before doing anything else, check for updates manually:

1. Open the app menu and go to About.
2. Proton Drive automatically checks for updates. If a newer version is available, click Update app.

3. Once the update is installed, restart the app and let sync run for a few minutes before checking whether the issue is resolved.

Alternatively, you can download the latest Proton Drive app for Windows and install it on your computer.

Check if the files are open in another app

Opening a file with another app (for example, if you’re working on a .doc file in Microsoft Word) will prevent it from being synced.

To successfully sync a file, close all other apps where it’s open and check the sync status in the Activities tab.

Folders and files synced to another cloud storage app

Files you sync you’ve synced to another cloud storage app might not get synced to Proton Drive if you store these files as online only.

To successfully sync these files, make sure these are set to Always keep on this device.

Pause and resume sync

If sync is not working, go to the Activity tab and click Pause sync. Wait a few seconds and click Resume sync.

Rename files with unsupported characters

If the files or folders you are trying to sync have names unsupported by Proton Drive, they will not be synced. When Drive detects an unsupported character, it flags the affected files. Here’s what you need to do:

1. Open the Activity tab and click Show more details to expand the list of items with sync issues.

2. For each file, check and confirm the “The name contains characters not supported by Windows” status, then click Rename.
3. Preview the suggested new name. You can leave it as it is (Proton Drive will replace the unsupported characters with safe equivalents) or edit it.

4. Click Save to apply changes. 

Proton Drive will automatically retry the sync once the file is renamed. It may take a short while for the change to propagate and for the file to appear as synced.

Sign out and back in

Sign out of the Proton Drive app and log back in to refresh the app’s session.

Check your network connection

Sync depends on a stable connection to Proton’s servers. If the app appears connected but isn’t making progress:

• Confirm that other apps and websites are loading normally to rule out a general network issue.
• If you’re connected to a VPN(nytt fönster) (including Proton VPN), try switching to a different server(nytt fönster). Some servers may be congested or may route traffic in a way that affects upload performance. After switching, give sync a minute to reconnect.
• If switching servers doesn’t help, try briefly disconnecting from the VPN to confirm whether it’s the source of the slowdown.