Sync is failing, see below:

1512724790192 Sync.Engine.Extension-Storage ERROR Syncing {73a6fe31-595d-460b-a920-fcc0f8843232}: request failed: Error: HTTP 507; Error: HTTP 507 Insufficient Storage: Resource access is forbidden for this user (Maximum bytes per object exceeded (17147 > 16384 Bytes.) (resource://services-common/kinto-http-client.js:2354:21) JS Stack trace: formatResponse@kinto-http-client.js:2377:21 < processResponse@kinto-http-client.js:2352:14 1512724790193 Sync.Engine.Extension-Storage WARN Syncing failed: Error: HTTP 507; Error: HTTP 507 Insufficient Storage: Resource access is forbidden for this user (Maximum bytes per object exceeded (17147 > 16384 Bytes.) (resource://services-common/kinto-http-client.js:2354:21) JS Stack trace: formatResponse@kinto-http-client.js:2377:21 < processResponse@kinto-http-client.js:2352:14 1512724790193 Sync.Status DEBUG Status for engine extension-storage: error.engine.reason.unknown_fail 1512724790193 Sync.Status DEBUG Status.service: success.status_ok => error.sync.failed_partial 1512724790193 Sync.ErrorHandler DEBUG extension-storage failed: Error: HTTP 507; Error: HTTP 507 Insufficient Storage: Resource access is forbidden for this user (Maximum bytes per object exceeded (17147 > 16384 Bytes.) (resource://services-common/kinto-http-client.js:2354:21) JS Stack trace: formatResponse@kinto-http-client.js:2377:21 < processResponse@kinto-http-client.js:2352:14 1512724790194 Sync.Telemetry TRACE observed weave:engine:sync:error extension-storage 1512724790194 Sync.Doctor INFO Skipping check of prefs - disabled via preferences 1512724790194 Sync.Doctor INFO Skipping check of passwords - disabled via preferences 1512724790194 Sync.Doctor INFO Skipping check of addons - disabled via preferences 1512724790194 Sync.Doctor INFO Skipping check of extension-storage - disabled via preferences 1512724790195 Sync.Doctor INFO Skipping validation: no engines qualify 1512724790195 Sync.Synchronizer INFO Sync completed at 2017-12-08 10:19:50 after 3.39 secs. 1512724790196 Sync.Declined DEBUG Handling remote declined: ["bookmarks","forms","history","tabs","adblockplus"] 1512724790196 Sync.Declined DEBUG Handling local declined: ["bookmarks","forms","history","tabs","adblockplus"] 1512724790196 Sync.Declined DEBUG Declined changed? false 1512724790196 Sync.Service INFO No change to declined engines. Not reuploading meta/global. 1512724790197 Sync.SyncScheduler DEBUG Next sync in 600000 ms. 1512724790198 Sync.ErrorHandler ERROR Some engines did not sync correctly. 1512724790198 Sync.Telemetry TRACE observed weave:service:sync:finish 1512724790202 Sync.ErrorHandler DEBUG Addons installed: 12 1512724790202 Sync.ErrorHandler DEBUG - Block Site, version 0.1.6, id {07046613-1993-4b66-9dd1-9dd1ce581cb7} 1512724790202 Sync.ErrorHandler DEBUG - Show my Password, version 1.2.0, id jid1-ytAaKUpYnPSfGA@jetpack 1512724790202 Sync.ErrorHandler DEBUG - Tab Suspender (memory saver), version 0.2.6, id {e225ac78-5e83-484b-a16b-b6ed0924212f} 1512724790202 Sync.ErrorHandler DEBUG - Print Edit WE, version 20.1, id printedit-we@DW-dev 1512724790203 Sync.ErrorHandler DEBUG - Undo Closed Tabs Button, version 0.1.4, id {5997e7bd-1940-4058-a5f4-1562afce6353} 1512724790203 Sync.ErrorHandler DEBUG - uBlock Origin, version 1.14.20, id uBlock0@raymondhill.net 1512724790203 Sync.ErrorHandler DEBUG - About Sync extension for Firefox, version 0.0.17, id aboutsync@mhammond.github.com 1512724790203 Sync.ErrorHandler DEBUG - Panic Button, version 4.0.1, id {24cea704-946d-11da-a72b-0800200c9a66} 1512724790203 Sync.ErrorHandler DEBUG - KeePassHttp-Connector, version 1.0.8, id keepasshttp-connector@addons.brandt.tech 1512724790203 Sync.ErrorHandler DEBUG - Tampermonkey, version 4.5.5633, id firefox@tampermonkey.net 1512724790203 Sync.ErrorHandler DEBUG - NoScript, version 10.1.5.5, id {73a6fe31-595d-460b-a920-fcc0f8843232} 1512724790203 Sync.ErrorHandler DEBUG - Speed Dial [FVD] New Tab Page, 3D Wall, Sync, version 64.3.5, id pavel.sherbakov@gmail.com