# ERROR: AGRIF hot start requires to force Euler first step on parent

**URL:** <https://nemo-ocean.discourse.group/t/error-agrif-hot-start-requires-to-force-euler-first-step-on-parent/978>\
**Category:** v4.2.x\
**Tags:** AGRIF\
**Created:** [13 January 2026 08:31 UTC](https://nemo-ocean.discourse.group/t/error-agrif-hot-start-requires-to-force-euler-first-step-on-parent/978 "2026-01-13T08:31:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![wangy](https://avatars.discourse-cdn.com/v4/letter/w/dec6dc/32.png) [@wangy](https://nemo-ocean.discourse.group/u/wangy)\
**Post date:** [13 January 2026 08:31 UTC](https://nemo-ocean.discourse.group/t/error-agrif-hot-start-requires-to-force-euler-first-step-on-parent/978/1 "2026-01-13T08:31:27Z")

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Hi everyone

I have been running a 10-year nested case. The AGRIF.in file is as follows.

> 1  
> 172 196 62 92 2 2 2  
> 1  
> 10 41 15 46 3 3 3  
> 0

Now, when I try to restart it, 1\_ocean.output\_00\* and 2\_ocean.output\_00\* both show the following error:

> ===\>\>\> : E R R O R
> 
> ```auto
> ===========
> 
> ```
> 
> AGRIF hot start requires to force Euler first step on parent
> 
> West ht0 hv0 iindic= 0  
> West hu0 iindic= 0  
> East ht0 hv0 iindic= 0  
> East hu0 iindic= 0  
> South ht0 hv0 iindic= 0  
> South hu0 iindic= 0  
> North ht0 hv0 iindic= 0  
> North hu0 iindic= 0  
> kindic\_agr= 0  
> kindic\_agr= 0
> 
> ===\>\>\> : E R R O R
> 
> ```auto
> ===========
> 
> ```
> 
> AGRIF hot start requires to force Euler first step on parent

Can anyone offer suggestions on how to restart a nested simulation? Thanks in advance!

```auto
                                                                     

```

---

<div class="post-metadata">

**Author:** ![wangy](https://avatars.discourse-cdn.com/v4/letter/w/dec6dc/32.png) [@wangy](https://nemo-ocean.discourse.group/u/wangy)\
**Post date:** [14 January 2026 15:52 UTC](https://nemo-ocean.discourse.group/t/error-agrif-hot-start-requires-to-force-euler-first-step-on-parent/978/2 "2026-01-14T15:52:50Z")

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I seem to have fixed this issue by adding “ln\_1st\_euler = .true” to all namelist\_cfg files. Thanks for your attention.