# Build fails when using FFrame::Step, somtimes

**URL:** <https://forums.unrealengine.com/t/build-fails-when-using-fframe-step-somtimes/464887>\
**Category:** Platform & Builds\
**Tags:** Replication, ufunction, build, unreal-engine, CPP, question\
**Created:** [May 8, 2020, 10:43pm UTC](https://forums.unrealengine.com/t/build-fails-when-using-fframe-step-somtimes/464887 "2020-05-08T22:43:51Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Panakotta00](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Panakotta00](https://forums.unrealengine.com/u/Panakotta00)\
**Post date:** [May 8, 2020, 10:43pm UTC](https://forums.unrealengine.com/t/build-fails-when-using-fframe-step-somtimes/464887/1 "2020-05-08T22:43:51Z")

</div>

OK, so I simply try to use FFrame::Step in a custom thunk function.  
When I now regenerate the VS project files and then build, the build will fail with all sorts of wierd errors.  
When I comment it, regenerate the VS project, then uncomment it again, and then build, it works just as intended.