# Error during backward integration with callback in DifferentialEquations.jl

**URL:** <https://discourse.julialang.org/t/error-during-backward-integration-with-callback-in-differentialequations-jl/128563>\
**Category:** New to Julia\
**Tags:** differentialequation\
**Created:** [April 30, 2025, 9:20am UTC](https://discourse.julialang.org/t/error-during-backward-integration-with-callback-in-differentialequations-jl/128563 "2025-04-30T09:20:29Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![remydutto](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/remydutto/32/216594_2.png) [@remydutto](https://discourse.julialang.org/u/remydutto)\
**Post date:** [April 30, 2025, 9:20am UTC](https://discourse.julialang.org/t/error-during-backward-integration-with-callback-in-differentialequations-jl/128563/1 "2025-04-30T09:20:29Z")

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Hi everyone,  
I was trying to run the following example

```julia-auto
using OrdinaryDiffEq

function dynamic!(dx, x, p, t)
    dx[1] = exp(-x[2] - sin(x[2])^2)
    dx[2] = 1. / (x[2] + 1.)
    dx[3] = 1.
end

x0 = [0., 1.0164282571836771, 0.]
cb = ContinuousCallback((x,_,_) -> x[2] , terminate!) 
prob = ODEProblem(dynamic!, x0, (2, 0))
sol = OrdinaryDiffEq.solve(prob, callback = cb)

```

and I get the following error `Current interpolant only works between tprev and t`. I don’t really know if I am doing something wrong or if it’s a bug.

Thank you for your help.

## Package info

```julia-auto
[1dea7af3] OrdinaryDiffEq v6.95.1

```

## Julia & platform info

```julia-auto
Julia Version 1.11.5
Commit 760b2e5b73 (2025-04-14 06:53 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 12 × 13th Gen Intel(R) Core(TM) i5-1335U
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, goldmont)
Threads: 1 default, 0 interactive, 1 GC (on 12 virtual cores)

```

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<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [April 30, 2025, 11:01am UTC](https://discourse.julialang.org/t/error-during-backward-integration-with-callback-in-differentialequations-jl/128563/2 "2025-04-30T11:01:38Z")

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Open an issue on OrdinaryDiffEq.jl and we’ll look into this in some detail. Looks like a bug where there’s a spot that isn’t robust to backwards integration.

---

<div class="post-metadata">

**Author:** ![remydutto](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/remydutto/32/216594_2.png) [@remydutto](https://discourse.julialang.org/u/remydutto)\
**Post date:** [April 30, 2025, 1:19pm UTC](https://discourse.julialang.org/t/error-during-backward-integration-with-callback-in-differentialequations-jl/128563/3 "2025-04-30T13:19:06Z")

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Thank you for your answer. Done in the issue [#2691](https://github.com/SciML/OrdinaryDiffEq.jl/issues/2691).