# I can't launch UEFN after changing an external SSD drive.

**URL:** <https://forums.unrealengine.com/t/i-cant-launch-uefn-after-changing-an-external-ssd-drive/2103258>\
**Category:** Issues and Bug Reporting\
**Tags:** fortnite-creative, unreal-editor-for-fortnite, question, fortnite\
**Created:** [November 3, 2024, 10:59pm UTC](https://forums.unrealengine.com/t/i-cant-launch-uefn-after-changing-an-external-ssd-drive/2103258 "2024-11-03T22:59:49Z")\
**Posts on this page:** 1\
**Showing post:** 2

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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:** [November 4, 2024, 5:04am UTC](https://forums.unrealengine.com/t/i-cant-launch-uefn-after-changing-an-external-ssd-drive/2103258/2 "2024-11-04T05:04:38Z")

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hi @masa_jpn007  
we had that before in this post  
[[Solved] How to fix Fatal Errors in UEFN related to Graphic Cards and Shaders and Derived Data problems - General / Issues and Bug Reporting - Epic Developer Community Forums](https://forums.unrealengine.com/t/solved-how-to-fix-fatal-errors-in-uefn-related-to-graphic-cards-and-shaders-and-derived-data-problems/2080832/9)

summary  
you need to add directory on example F:  
F:\Program Files\Epic Games  
Then you can install UEFN  
Program Files\Epic Games\ ON drive needs to be made

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