# 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:** 19

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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 24, 2024, 1:31am UTC](https://forums.unrealengine.com/t/session-not-launching-after-renaming-ambiguous-materials-parameter-verse-building-manually-works/1981528/19 "2024-08-24T01:31:24Z")

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hi @cr1pzzy  
There are similar Verse Color errors reported

> [@COLOR VERSE ERROR](https://forums.unrealengine.com/t/color-verse-error/1981493/4):
>
> We have not touched any of these materials, since they were created a long time ago, the problem is Error: C:/Users/Brandom/Downloads/RICHVSPOOR/Plugins/RICHVSPOOR/sys/published/Assets/Assets.verse(1258,19, 1258,24): Script error 3588: Ambiguous identifier; Could be danieloviss@fortnite.com.RICH\_VS\_POOR.IMAGENES.RojoKills\_material.color or Verse.org.Colors.color, we have tried everything, eliminating materials, changing everything, names… etc, but nothing, since the new fortnite update has sta…

> [@Unable to publish after renaming ambiguous material parameter - verse color error.](https://forums.unrealengine.com/t/unable-to-publish-after-renaming-ambiguous-material-parameter-verse-color-error/1985381/2):
>
> hi @chefenmaps , Possibly the answer to Verse Persistence problems were cleared in this post [Verse Persistence incompatible without editing the verse file that contains it](https://forums.unrealengine.com/t/verse-persistence-incompatible-without-editing-the-verse-file-that-contains-it/1956674/2) and documentation [Using Persistable Data in Verse | Unreal Editor for Fortnite Documentation](https://dev.epicgames.com/documentation/en-us/uefn/using-persistable-data-in-verse)

The problem was once talked about as Fix Asset function on Verse path ,  
just cannot see why that would work  
A

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