Error when trying to login to Org while using Lightning Experience

Last updated 2017-04-14 ·Reference W-3427864 ·Reported By 29 users

Fixed - Winter '17 Patch 12.0

Summary
After Winter '17 update some are unable to login to their orgs, and are receiving the following error:

"Something has gone wrong. Error in $A.getCallback() [Unfortunately, there was a problem. Please try again. If the problem continues, get in touch with your administrator with the error ID shown here and any other related details.
Event fired]
Failing descriptor: {markup://one:one}.
Please try again."

Repro
After Winter '17 release:
1) login with user with LEX enabled
2) You will see error and unable to login to org

Workaround
You can change the URL in browser and then disable Lightning Experience to be able to login to org.

1) Add URL in browser after receiving error: replace /one/one.app with /setup/forcecomHomepage.apexp
2) Click on "Lightning Experience"
3) disable LEX

Is it Fixed?

AP0 AP1 AP2 AP3 AP4 AP5 AP9 CS1 CS2 CS3 CS4 CS5 CS6 CS7 CS8 CS9 CS10 CS11 CS116 CS115 CS12 CS13 CS14 CS15 CS16 CS17 CS18 CS19 CS20 CS21 CS22 CS23 CS24 CS25 CS26 CS27 CS28 CS30 CS31 CS32 CS33 CS40 CS41 CS42 CS43 CS44 CS45 CS47 CS50 CS51 CS52 CS53 CS54 CS57 CS58 CS59 CS60 CS61 CS62 CS63 CS64 CS65 CS66 CS67 CS68 CS69 CS70 CS71 CS72 CS77 CS78 CS79 CS80 CS81 CS82 CS83 CS84 CS85 CS86 CS87 CS88 CS89 CS90 CS91 CS92 CS93 CS94 CS95 CS96 CS97 CS98 CS99 EU1 EU2 EU3 EU4 EU5 EU6 EU7 EU9 EU11 NA2 NA3 NA6 NA7 NA8 NA18 NA21 NA22 NA23 NA24 NA28 NA29 NA30 NA31 NA32 NA33 NA34 NA35 NA37 NA38 NA39 NA40 NA41 NA42 NA43 NA44 NA45 NA46 NA47 NA48 NA49 NA50 NA51 NA52 NA53 NA54 NA55 NA56 NA57 NA58 NA59 NA60 NA61 NA62 NA63 NA64 NA67 NA68 NA73 NA74 NA78 NA79 NA88 NA99

Any unreleased services, features, statuses, or dates referenced in this or other public statements are not currently available and may not be delivered on time or at all. Customers who purchase our services should make their purchase decisions based upon features that are currently available.