"Sync is currently experiencing problems. it will be back shortly" = topic. I welcome all to read & help if possible because mine has been a very long issue. The following is for those who won't be bored by extreme detail because this posting has huge degree of detail.
"subts10", I restored Calendar after following your instructions, and step by step, adding in various check-marks of sync - browser, chrome, Google photos, Google play books, Google play magazines, movies & TV with ALL creating NO problem, some after long cycling, Gmail followed suit but Contacts (for 2 accounts only) immediately brings up the well-known "Sync is currently experiencing problems. it will be back shortly."
For these 2 accounts only, additionally listed with the stamp showing the famous lower case "g" on blue field & now that I've been working with this info for awhile, realize that apparently, it's key that only under the stamp of this blue g is the "Contacts" category making this Sync to misbehave or perhaps, not key-it just seems odd that since it is the only place that it exists, how would it be not significant in any way whatsoever?
The remainder is detail of interest only to specialist - hopefully, it will make sense leading to resolution of this nagging issue (for my since early last summer, when I got this phone)
On this phone, I list 6 email accounts which are listed in extreme detail, shown what Sync options are available:
1. Calendar, Contacts, Email, base email for prior phone, rarely used, stamp=white envelope, @+ red field
2. Sync Email = only option, same as #1 account but stamp @ with red field.
3. Calendar, Contacts, Email, stamp=open white envelope with @ surrounded by red field
4. Calendar, Contacts, Email, stamp=open white envelope with @ surrounded by red field
5. Calendar, Contacts, (outlook.com account)
6. Most used account - Browser, Calendar, Chrome (shown only here), Contacts (no check-mark), Gmail, Google Photos, Play Books, Magazines, Movies & TV.
7. Browser, Calendar, Contacts, Gmail, Google Photos, Play Books, Magazines, Movies & TV, Sync Google+ & Sync Instant Upload but adding Contacts check-mark creates sync issue. Category shows that "Sync is ON" whether listed under g on blue field (with these 11 categories) or stamp showing @ on red field, listing just Sync Email & all others except one are simply listed & all show that Sync is ON
8. MotoCast ID, no sync options available
9. Sync email, same account as #6 but just 1 option- what contrast to most used account!
10. Phone number, visual voicemail
11. Backup Assistant Plus
12. Facebook Sync Contacts
13. Facebook No Sync options but listed under Sync Settings, Duh!
14. Dropbox - no options, shows Account Settings and Data & Synchronization beyond General Settings
15. Sync Email, for #7 account second most used
Well, good luck to those who read and might have suggestions as to what fixes might help. I'm open to trying new things and really am overly due for something to work. Thanks to all who offer suggestions. Please make it worth the time it took giving you the info!
So wondering if for 6 email accounts if it's typical to have 15 things listed under Accounts and Sync? OK, very tired and giving up - hoping someone will have a solution for me. Bye, Sandra