# Inconsistent Issue with Periodic Condition

**URL:** <https://community.freefem.org/t/inconsistent-issue-with-periodic-condition/2807>\
**Category:** General Discussion\
**Created:** [November 16, 2023, 8:40pm UTC](https://community.freefem.org/t/inconsistent-issue-with-periodic-condition/2807 "2023-11-16T20:40:01Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![FluidMan](https://avatars.discourse-cdn.com/v4/letter/f/e68b1a/32.png) [@FluidMan](https://community.freefem.org/u/FluidMan)\
**Post date:** [November 16, 2023, 8:40pm UTC](https://community.freefem.org/t/inconsistent-issue-with-periodic-condition/2807/1 "2023-11-16T20:40:01Z")

</div>

Hi all!

So I have a 3d mesh that works whenever I use:

fespace Vh3(Th3,[P2,P2,P2,P1]);

but not:

fespace Vh3p(Th3, P2, periodic=[[Face1, y,z],[Face3, y,z]]);

Crazy enough it does work sometimes if I change the size of Face1 and Face3 but not all sizes! Any thoughts on why this could possibly be? I have been troubleshooting all week and just need some direction. Below is an example of the error I get:

missing Border element : 308 180 181 184  
missing Border element : 309 181 184 185  
missing Border element : 310 176 177 180  
missing Border element : 311 177 180 181  
missing Border element : 312 170 171 176  
missing Border element : 313 171 176 177  
missing Border element : 314 164 165 170  
missing Border element : 315 165 170 171  
missing Border element : 316 158 159 164  
missing Border element : 317 159 164 165  
missing Border element : 318 152 153 158  
missing Border element : 319 153 158 159  
missing Border element : 320 146 147 152  
missing Border element : 321 147 152 153  
3d periodic FE: number of missing periodic faces 14  
current line = 212  
Exec error : 3d periodic condition missing common face  
– number :1  
Exec error : 3d periodic condition missing common face  
– number :1  
err code 8 , mpirank 0

-Dylan