Brave Sync is causing crashes and bookmark duplication

Description

In the past ~24 hours, Brave Sync has started crashing my Brave Beta Browser on Linux repeatedly ~20 seconds after loading (repeatable 10+ times). It also duplicates bookmarks sometimes.

Temporarily disabling Bookmark sync made the browser stable, so I can now use it. Re-enabling Bookmark syncing began the crashes again.

See possibly related recent discussion threads here and here.

Steps to Reproduce

(Not sure if reproducible on all Linux machines)

1. Open Brave Beta, wait 20 seconds
2. Browser crashes
3. Re-open Brave Beta and disable Sync
4. Stable
5. Re-enable Brave Sync, wait 20 seconds
6. Browser crashes

Actual result:

Crashes, duplicates bookmarks and bookmark folders. Interestingly not all bookmarks/folders are affected. I have some that are duplicated 0, 1, 2, or 3 times. When the folders duplicate, sometimes the contents inside do and sometimes they do not.

Bookmarks have not been duplicated on Windows or iOS. Duplication issue appears to be local to this Linux machine only for now.

Expected result:

Sync without crashing or duplication.

Reproduces how often:

Every time for me on Linux, never on Windows machine or iOS

Brave version (brave://version info)

Brave	0.69.119 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Linux

Version/Channel Information:

Have not tried other versions on Linux and am not planning to unless needed. Other versions wouldn’t be part of my sync chain anyway if I understand Sync limitations correctly.

Other Additional Information:

Also in my sync chain are 2 Windows machines and 1 iOS.

Miscellaneous Information:

Here is an example crash report. I have dozens more if needed. Let me know. f3083bd71ed7090e

[bsclifton]

This is definitely a known issue - thanks for the report! @darkdh is looking into this now and is working on some fixes

I’m going to close this issue in favor of the main tracking issue that we have: https://github.com/brave/brave-browser/issues/6091

[michaeladler]

I also had the problem of duplicated bookmarks. Crashing isn’t fixed though with 0.70.93, at least on my machine. I have disabled sync now, which prevents the crashes. FWIW, I’ve used an extension called SuperSorter to get rid of the duplicated bookmarks.