# "Oops, we could not run this project. Please check your code for errors."

**URL:** https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589
**Category:** Help
**Created:** [June 18, 2026, 2:13am UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589 "2026-06-18T02:13:31Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![harithrizqi](https://avatars.discourse-cdn.com/v4/letter/h/df705f/32.png) [@harithrizqi](https://forum.makecode.com/u/harithrizqi)
#### Post date: [June 18, 2026, 2:13am UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589/1 "2026-06-18T02:13:31Z")

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[https://arcade.makecode.com/S94622-46837-25710-97038](https://arcade.makecode.com/S94622-46837-25710-97038)

I just running this simulator - doesn’t it works!

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### Author: ![VoxelMaster64](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/voxelmaster64/32/32075_2.png) [@VoxelMaster64](https://forum.makecode.com/u/VoxelMaster64)
#### Post date: [June 18, 2026, 4:46pm UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589/2 "2026-06-18T16:46:20Z")

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> **[Cave Story](https://arcade.makecode.com/S18601-09454-20398-53764)**
>
> Made with ❤️ in Microsoft MakeCode Arcade.

I don’t know any python 😭

the issue was that `player` is defined somewhere by makecode, so I renamed it to `p`. The `on start` function also shouldn’t exist (unless you call it) because it wasn’t running.

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### Author: ![WoofWoof](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/woofwoof/32/32523_2.png) [@WoofWoof](https://forum.makecode.com/u/WoofWoof)
#### Post date: [June 18, 2026, 4:56pm UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589/3 "2026-06-18T16:56:16Z")

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When you create a variable inside a function, it is only “local” to that function and gets deleted once the function is done running. You have to make it outside of the function or use the “global” keyword to make it a global variable.

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### Author: ![ThatCoder](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.makecode.com/thatcoder/32/29388_2.png) [@ThatCoder](https://forum.makecode.com/u/ThatCoder)
#### Post date: [June 18, 2026, 10:18pm UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589/4 "2026-06-18T22:18:18Z")

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Welcome to forums @harithrizqi !

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### Author: ![harithrizqi](https://avatars.discourse-cdn.com/v4/letter/h/df705f/32.png) [@harithrizqi](https://forum.makecode.com/u/harithrizqi)
#### Post date: [July 4, 2026, 6:36pm UTC](https://forum.makecode.com/t/oops-we-could-not-run-this-project-please-check-your-code-for-errors/44589/5 "2026-07-04T18:36:30Z")

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[Cave Story](https://arcade.makecode.com/S28217-21834-96828-03712)

It worked!