cubicweb-brainomics #3023185 admin: manage doesn't work anymore [deprecated]

After logging in as "admin" I am unable to manage the server:

* Adding a user doesn't work. I've started by clicking on "New user". Then I filled in the form. Finally I hit "Validate" and nothing happened: I remained on the same page and the user was not created. No error message or explanations.

* I've tried changing the site title in site configuration / ui. Modyfying the title and clicking "Validate" yields:

0 : A
startswith : function (prefix) { return this.indexOf(prefix) == 0; }
endswith : function (suffix) { var startPos = this.length - suffix.length; if (startPos < 0) { return false; } return this.lastIndexOf(suffix, startPos) == startPos; }
strip : function () { return this.replace(/^\s*(.*?)\s*$/, "$1"); }
rstrip : function (str) { if (!str) { str = '\s' ; } return this.replace(new RegExp('^(.*?)' + str + '*$'), "$1"); }
! please correct errors below

Maybe bootstrap issues?

prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>