# Announcement: JuMP 0.16 released
**URL:** https://discourse.julialang.org/t/announcement-jump-0-16-released/2289
**Category:** Optimization (Mathematical)
**Created:** [February 24, 2017, 10:17pm UTC](https://discourse.julialang.org/t/announcement-jump-0-16-released/2289 "2017-02-24T22:17:00Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@miles.lubin](https://discourse.julialang.org/u/miles.lubin)
#### Post date: [February 24, 2017, 10:17pm UTC](https://discourse.julialang.org/t/announcement-jump-0-16-released/2289/1 "2017-02-24T22:17:01Z")
We’re pleased to announce the release of JuMP 0.16. The release has **three breaking changes** that may affect many users, so keep reading.
1. JuMP’s method for loading default solvers was a source of confusion and not compatible with Julia 0.6, so we decided to drop it. Not specifying a solver (via either the `solver=` keyword to `Model()` or the `setsolver()` method) before calling `solve()` is now an error.
2. As [previously announced](https://discourse.julialang.org/t/upcoming-breaking-change-in-jump-with-user-defined-functions/1191), user-defined functions are now defined within the scope of a model. Calling `JuMP.register` without providing a `Model` object as the first argument will result in an error.
3. `setvalue` had some magical behavior for fixed variables which was removed. In order to prevent silent behavior changes, calling `setvalue` on a fixed variable will result in an error for the time being. Use the new `JuMP.fix` instead.
See [NEWS](https://github.com/JuliaOpt/JuMP.jl/blob/5735b54e98cad041af3606b2b1dbccc0c573b440/NEWS.md#version-0160-february-23-2017) for a longer list including non-breaking changes. Notably, JuMP is passing tests on Julia 0.6-dev. We are not yet free of deprecation warnings, though (PRs welcome).
Happy JuMPing!
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### Author:  [@miles.lubin](https://discourse.julialang.org/u/miles.lubin)
#### Post date: [February 24, 2017, 10:33pm UTC](https://discourse.julialang.org/t/announcement-jump-0-16-released/2289/2 "2017-02-24T22:33:06Z")