# Session not launching after renaming ambiguous materials parameter, verse building manually works.

**URL:** <https://forums.unrealengine.com/t/session-not-launching-after-renaming-ambiguous-materials-parameter-verse-building-manually-works/1981528>\
**Category:** Issues and Bug Reporting\
**Tags:** fortnite-creative, unreal-editor-for-fortnite, fortnite\
**Created:** [August 18, 2024, 2:05pm UTC](https://forums.unrealengine.com/t/session-not-launching-after-renaming-ambiguous-materials-parameter-verse-building-manually-works/1981528 "2024-08-18T14:05:42Z")\
**Posts on this page:** 1\
**Showing post:** 17

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**Author:** ![Jimbohalo10](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/jimbohalo10/32/961440_2.png) [@Jimbohalo10](https://forums.unrealengine.com/u/Jimbohalo10)\
**Post date:** [August 22, 2024, 11:51pm UTC](https://forums.unrealengine.com/t/session-not-launching-after-renaming-ambiguous-materials-parameter-verse-building-manually-works/1981528/17 "2024-08-22T23:51:32Z")

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hi all,  
You are best following the thread/post  
[Fortnite Ecosystem v31.00 with Known Issues](https://forums.unrealengine.com/t/fortnite-ecosystem-v31-00-with-known-issues/1978173/11)

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