Gmailアプリは再び同期を停止しました -- sync フィールド android 関連 問題

Two different devices, a Nexus 7 tablet and Moto X. Both running last Kit Kat update. Nexus has Gmail app 5.1, Moto X has Gmail app 4.9. Gmail on my computer works fine. Both devices last synced 2 days ago at same time and neither will sync even manually now. Both worked just fine until 2 days ago. All other Google apps sync fine, only my Gmail doesn't. Since Gmail on my computer is fine and two separate devices using 2 different Gmail app updates don't sync, it seems like it has to do with my Gmail account or with the Google server, not the Gmail app per ae .Why did 2 devices stop at same time with my computer working just fine? Haven't been able to receive or send emails or draft emails from Nexus or Moto X for 2 days. Again, all other Google apps manually sync on both devices but Gmail will not on either. Don't see that this is another widespread sync problem like last June. Please advise. Thanks.

Just now, 51 hours after the sync failure problem began,my tablet and phone both started Gmail manual syncing again. No fix was applied. I can only assume therefore it was a Google issue and not my account, devices or the app. The only unifying root cause would be a Google server issue or my Gmail account, and that account always worked on my computer. Hopefully it will remain functional.