error: Potentially incompatible change required to top-level dependency

[lc3t35]

% meteor update
This project is already at Meteor 1.2.1, the latest release.
=> Errors while upgrading packages:           

While selecting package versions:
error: Potentially incompatible change required to top-level dependency: orionjs:core 1.6.0, was 1.7.0.
Constraints on package "orionjs:core":
* orionjs:[email protected] <- orionjs:bootstrap 1.6.0
* orionjs:[email protected] <- vsivsi:orion-file-collection 0.2.2

Potentially incompatible change required to top-level dependency: orionjs:bootstrap 1.6.0, was 1.7.0.
Constraints on package "orionjs:bootstrap":

Potentially incompatible change required to top-level dependency: orionjs:filesystem 1.6.0, was 1.7.0.
Constraints on package "orionjs:filesystem":
* orionjs:[email protected] <- vsivsi:orion-file-collection 0.2.2
* orionjs:[email protected] <- orionjs:summernote 1.6.0
* orionjs:[email protected] <- orionjs:froala 1.6.0
* orionjs:[email protected] <- orionjs:image-attribute 1.6.0

Potentially incompatible change required to top-level dependency: orionjs:summernote 1.6.0, was 1.7.0.
Constraints on package "orionjs:summernote":

Potentially incompatible change required to top-level dependency: orionjs:froala 1.6.0, was 1.7.0.
Constraints on package "orionjs:froala":

Potentially incompatible change required to top-level dependency: orionjs:image-attribute 1.6.0, was 1.7.0.
Constraints on package "orionjs:image-attribute":

Potentially incompatible change required to top-level dependency: orionjs:relationships 1.6.0, was 1.7.0.
Constraints on package "orionjs:relationships":

Potentially incompatible change required to top-level dependency: orionjs:lang-es 1.6.0, was 1.7.0.
Constraints on package "orionjs:lang-es":

To allow potentially incompatible changes to top-level dependencies, you must pass --allow-incompatible-update on the command line.

Launching as suggested :
% meteor --allow-incompatible-update
downgrades orionjs to 1.6.0 :(

meteor --allow-incompatible-update
[[[[[ ~/dev/meteor/orionjs-examples/blog ]]]]]

=> Started proxy.                             
=> Started MongoDB.                           

Changes to your project's package version selections:

orionjs:accounts         downgraded from 1.7.0 to 1.6.0
orionjs:attributes       downgraded from 1.7.0 to 1.6.0
orionjs:base             downgraded from 1.7.0 to 1.6.0
orionjs:bootstrap        downgraded from 1.7.0 to 1.6.0
orionjs:collections      downgraded from 1.7.0 to 1.6.0
orionjs:config           downgraded from 1.7.0 to 1.6.0
orionjs:core             downgraded from 1.7.0 to 1.6.0
orionjs:dictionary       downgraded from 1.7.0 to 1.6.0
orionjs:filesystem       downgraded from 1.7.0 to 1.6.0
orionjs:froala           downgraded from 1.7.0 to 1.6.0
orionjs:image-attribute  downgraded from 1.7.0 to 1.6.0
orionjs:lang-en          downgraded from 1.7.0 to 1.6.0
orionjs:lang-es          downgraded from 1.7.0 to 1.6.0
orionjs:relationships    downgraded from 1.7.0 to 1.6.0
orionjs:summernote       downgraded from 1.7.0 to 1.6.0

I20151121-17:37:36.542(1)? Orion config initialized
I20151121-17:37:36.544(1)? Orion dictionary initialized
=> Started your app.

=> App running at: http://localhost:3000/

Where does this error come from ?