# Error (no connexe boundary be careful with internal boundary (pb of sens) ) : nb start = 2

**URL:** <https://community.freefem.org/t/error-no-connexe-boundary-be-careful-with-internal-boundary-pb-of-sens-nb-start-2/2356>\
**Category:** General Discussion\
**Created:** [March 25, 2023, 9:21am UTC](https://community.freefem.org/t/error-no-connexe-boundary-be-careful-with-internal-boundary-pb-of-sens-nb-start-2/2356 "2023-03-25T09:21:53Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![yongxing](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/yongxing/32/3632_2.png) [@yongxing](https://community.freefem.org/u/yongxing)\
**Post date:** [March 25, 2023, 9:21am UTC](https://community.freefem.org/t/error-no-connexe-boundary-be-careful-with-internal-boundary-pb-of-sens-nb-start-2/2356/1 "2023-03-25T09:21:53Z")

</div>

Does anyone have an idea what’s going wrong?  
The first remeshing works perfectly fine, but the second time of remeshing shows the this error;

> error (no connexe boundary be careful with internal boundary (pb of sens) ) : nb start = 2

[hydrogel\_2.edp](https://community.freefem.org/uploads/short-url/7WB3FmwkQ6u7YHJ50Qa00ATtpPU.edp) (4.3 KB)

---

<div class="post-metadata">

**Author:** ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)\
**Post date:** [March 30, 2023, 12:09pm UTC](https://community.freefem.org/t/error-no-connexe-boundary-be-careful-with-internal-boundary-pb-of-sens-nb-start-2/2356/2 "2023-03-30T12:09:06Z")

</div>

The code extractborder works only on connexe part.  
so call it for each connexe part by setting the label