https://support.mozilla.org/en-US/questions/1257728

You can open <b>about:sync-log</b> via the location bar to see whether recent Sync logs are available. You can upload the file to a website like Pastebin if you can't post the content of the file in a reply. *https://pastebin.com/

1617973933951 Sync.SyncScheduler DEBUG Next sync in 600000 ms. (why=schedule) 1617973933956 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973933957 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973940062 Sync.RemoteTabs INFO Generating tab list with filter 1617973940063 Sync.RemoteTabs DEBUG Processing client: {"id":"1d2488db5ce6531ce6fd7a4ab1eccab9","type":"client","name":"Firefox στο samsung SM-G988B","clientType":"phone","lastModified":1617959649170,"tabs":[]} 1617973940063 Sync.RemoteTabs INFO Final tab list has 1 clients with 0 tabs. 1617973948147 FirefoxAccounts DEBUG FxAccountsWebChannel message received: fxaccounts:fxa_status 1617973948147 FirefoxAccounts ERROR Rejected FxA webchannel message from remoteType = web 1617973953906 Sync.SyncScheduler DEBUG Global Score threshold hit, triggering sync. 1617973953907 Sync.Service DEBUG User-Agent: Firefox/87.0 (Windows NT 10.0; Win64; x64) FxSync/1.89.0.20210318103112.desktop 1617973953907 Sync.Service INFO Starting sync at 2021-04-09 16:12:33 in browser session 2vDtBPEaLkhW 1617973953907 Sync.SyncScheduler DEBUG Clearing sync triggers and the global score. 1617973953911 Sync.Status INFO Resetting Status. 1617973953911 Sync.Status DEBUG Status.service: success.status_ok => success.status_ok 1617973953912 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973953912 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973953912 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973954152 Sync.Resource DEBUG GET success 200 https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/info/collections 1617973954153 Sync.Service DEBUG Fetching server configuration: https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/info/configuration 1617973954153 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973954346 Sync.Resource DEBUG GET success 200 https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/info/configuration 1617973954346 Sync.Service DEBUG Fetching global metadata record 1617973954346 Sync.Service DEBUG Weave Version: 1.89.0 Local Storage: 5 Remote Storage: 5 1617973954346 Sync.Service DEBUG Fetching and verifying -- or generating -- symmetric keys. 1617973954346 Sync.Service INFO Testing info/collections: {"meta":1617960606.53,"history":1617973932.63,"prefs":1617973799.43,"clients":1617973798.87,"crypto":1617958115.72,"tabs":1617973924.06,"forms":1617973876.55,"passwords":1617973923.78,"bookmarks":1617973932.3,"addons":1617973801.32} 1617973954346 Sync.CollectionKeyManager INFO Testing for updateNeeded. Last modified: 1617958115.72 1617973954346 Sync.Synchronizer DEBUG Refreshing client list. 1617973954346 Sync.Engine.Clients INFO 0 outgoing items pre-reconciliation 1617973954346 Sync.Engine.Clients DEBUG Resetting clients last sync time 1617973954347 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973954559 Sync.Collection DEBUG GET success 200 https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/storage/clients?full=1&limit=1000 1617973954561 Sync.Engine.Clients INFO Records: 0 applied, 0 successfully, 0 failed to apply, 0 newly failed to apply, 3 reconciled. 1617973954561 Sync.Engine.Clients DEBUG Refreshing the known stale clients list 1617973954562 Sync.BulkKeyBundle INFO BulkKeyBundle being created for undefined 1617973954563 Sync.Engine.Clients INFO Hiding stale client SAdURWvhEPu6 - in known stale clients list 1617973954566 Sync.Synchronizer INFO Updating enabled engines: 2 clients. 1617973954567 Sync.Synchronizer INFO Syncing all enabled engines. 1617973954567 Sync.Engine.Prefs INFO 0 outgoing items pre-reconciliation 1617973954567 Sync.Engine.Prefs INFO Records: 0 applied, 0 successfully, 0 failed to apply, 0 newly failed to apply, 0 reconciled. 1617973954569 Sync.Engine.Passwords INFO 0 outgoing items pre-reconciliation 1617973954569 Sync.Engine.Passwords INFO Records: 0 applied, 0 successfully, 0 failed to apply, 0 newly failed to apply, 0 reconciled. 1617973954569 Sync.Engine.Tabs INFO 1 outgoing items pre-reconciliation 1617973954570 Sync.Engine.Tabs INFO Records: 0 applied, 0 successfully, 0 failed to apply, 0 newly failed to apply, 0 reconciled. 1617973954590 Sync.Engine.Tabs INFO Posting 1 records of 5202 bytes with batch=true 1617973954590 FirefoxAccounts TRACE not checking freshness of profile as it remains recent 1617973954591 Sync.Collection DEBUG POST Length: 5202 1617973954841 Sync.Collection DEBUG POST success 200 https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/storage/tabs?batch=true&commit=true 1617973954845 Sync.Engine.Bookmarks DEBUG Checking if server sync ID v2kKfFDfJI0p matches existing 1617973954846 Sync.Engine.Bookmarks INFO 0 outgoing items pre-reconciliation 1617973954848 Sync.Engine.Bookmarks INFO Records: 0 applied, 0 successfully, 0 failed to apply, 0 newly failed to apply, 0 reconciled. 1617973954848 Sync.Engine.Bookmarks.Mirror DEBUG Merging bookmarks in Rust 1617973954850 Sync.Engine.Bookmarks.Mirror DEBUG Building local tree 1617973954851 Sync.Engine.Bookmarks.Mirror DEBUG Building remote tree 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Building merged tree 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Applying merged tree 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Updating local items in Places 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Cleaning up observer notifications left from last sync 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Inserting Places for new items 1617973954852 Sync.Engine.Bookmarks.Mirror DEBUG Updating origins for new URLs 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Staging apply remote item ops 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Staging change GUID ops 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Staging apply new local structure ops 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Removing tombstones for revived items 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Inserting new tombstones for non-syncable and invalid items 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Removing local items 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Changing GUIDs 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Applying remote items 1617973954854 Sync.Engine.Bookmarks.Mirror DEBUG Recording item added notifications for new items 161797395481617978827829 Sync.SyncScheduler DEBUG Next sync in 600000 ms. (why=schedule) 1617978827958 Services.Common.RESTRequest DEBUG GET https://profile.accounts.firefox.com/v1/profile 304 1617979278234 Sync.SyncScheduler DEBUG Network link status changed to "down". Offline?: false 1617979278235 Sync.SyncScheduler DEBUG Clearing sync triggers and the global score. 1617979278237 Sync.SyncScheduler DEBUG Next sync in 600000 ms. (why=schedule) 1617979278243 Sync.SyncScheduler DEBUG Network link status changed to "down". Offline?: false 1617979278243 Sync.SyncScheduler DEBUG Clearing sync triggers and the global score. 1617979297207 Sync.SyncScheduler DEBUG Woke from sleep. 1617979297208 Sync.SyncScheduler DEBUG Woke from sleep. 1617979297208 Sync.SyncScheduler DEBUG Woke from sleep. 1617979297391 Sync.SyncScheduler DEBUG Online, will sync in 2s. 1617979297391 Sync.SyncScheduler DEBUG Next sync in 2000 ms. (why=wake_notification) 1617979297392 Sync.SyncScheduler DEBUG Online, will sync in 2s. 1617979297393 Sync.SyncScheduler DEBUG Online, will sync in 2s. 1617979297394 Sync.SyncScheduler DEBUG Network link status changed to "changed". Offline?: false 1617979299404 Sync.Service DEBUG User-Agent: Firefox/87.0 (Windows NT 10.0; Win64; x64) FxSync/1.89.0.20210318103112.desktop 1617979299404 Sync.Service INFO Starting sync at 2021-04-09 17:41:39 in browser session 2vDtBPEaLkhW 1617979299404 Sync.SyncScheduler DEBUG Clearing sync triggers and the global score. 1617979299408 Sync.Status INFO Resetting Status. 1617979299408 Sync.Status DEBUG Status.service: success.status_ok => success.status_ok 1617979299408 FirefoxAccounts DEBUG FxAccountsProfileClient: Requested profile 1617979299408 FirefoxAccounts DEBUG getOAuthToken enter 1617979299409 FirefoxAccounts TRACE getCachedToken returning cached token 1617979299409 FirefoxAccounts DEBUG getOAuthToken returning a cached token 1617979299409 Services.Common.RESTRequest DEBUG GET request to https://profile.accounts.firefox.com/v1/profile 1617979299414 Services.Common.RESTRequest DEBUG GET https://profile.accounts.firefox.com/v1/profile failed: 2152398878 - NS_ERROR_UNKNOWN_HOST 1617979299414 FirefoxAccounts ERROR Background refresh of profile failed: {"name":"FxAccountsProfileClientError","code":null,"errno":998,"error":"NETWORK_ERROR","message":"[Exception... \"NS_ERROR_UNKNOWN_HOST\" nsresult: \"0x804b001e (NS_ERROR_UNKNOWN_HOST)\" location: \"JS frame :: resource://services-common/rest.js :: onStopRequest :: line 488\" data: no]"} 1617979299416 Sync.Resource WARN GET request to https://sync-1-us-west1-g.sync.services.mozilla.com/1.5/184425432/info/collections failed: [Exception... "The lookup of the hostname failed" nsresult: "0x804b001e (NS_ERROR_UNKNOWN_HOST)" location: "<unknown>" data: no] No traceback available 1617979299416 Sync.Status DEBUG Status.sync: success.sync => error.login.reason.network 1617979299416 Sync.Status DEBUG Status.service: success.status_ok => error.sync.failed 1617979299416 Sync.ErrorHandler ERROR Sync encountered an error: [Exception... "The lookup of the hostname failed" nsresult: "0x804b001e (NS_ERROR_UNKNOWN_HOST)" location: "<unknown>" data: no] No traceback available