# Problem opening projects

**URL:** <https://forums.unrealengine.com/t/problem-opening-projects/1953713>\
**Category:** Rendering\
**Tags:** unreal-engine, question\
**Created:** [July 28, 2024, 10:46pm UTC](https://forums.unrealengine.com/t/problem-opening-projects/1953713 "2024-07-28T22:46:18Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![aleks7kman](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@aleks7kman](https://forums.unrealengine.com/u/aleks7kman)\
**Post date:** [July 28, 2024, 10:46pm UTC](https://forums.unrealengine.com/t/problem-opening-projects/1953713/1 "2024-07-28T22:46:18Z")

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An error appears when opening most projects. Projects can be opened 10 times. An empty project opens immediately. Reinstalled Windows and all drivers. Help me understand the cause of the error.

 ![Screenshot_99](https://d3kjluh73b9h9o.cloudfront.net/original/4X/d/0/4/d04402e7d944c64052bd675ff475fa40d2a5c9d7.png)

Assertion failed: ReaderPos + Num \<= ReaderSize [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Serialization\BufferReader.h] [Line: 52]

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**Author:** ![Quetzalcodename](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Quetzalcodename](https://forums.unrealengine.com/u/Quetzalcodename)\
**Post date:** [July 29, 2024, 10:01am UTC](https://forums.unrealengine.com/t/problem-opening-projects/1953713/2 "2024-07-29T10:01:11Z")

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Hey @aleks7kman,

Looks like your project may be trying to reference some deleted files. You may need to delete/remove your config folder to open the projects, however, that would mean resetting up a lot of controls, etc. Check out this thread that has a possible solution outside of deleting the config file:

> [@Assertion failed: ReaderPos + Num \<= ReaderSize](https://forums.unrealengine.com/t/assertion-failed-readerpos-num-readersize/454174):
>
> Getting this error on package: UATHelper: Packaging (Windows (64-bit)): LogWindows: Error: Assertion failed: ReaderPos + Num \<= ReaderSize [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Core\Public\Serialization/BufferReader.h] [Line: 53] I’m not very familiar with serialization in UE4, I don’t believe any of my code calls anything in those classes directly. No other errors in the log. Last successfully packaged a month ago, reverting until then to see what’s causing it but no luck yet. I s…

You can also try and verify your engine version to see if that resolves the issue.

Let me know if any of these work for you!

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**Author:** ![Quetzalcodename](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Quetzalcodename](https://forums.unrealengine.com/u/Quetzalcodename)\
**Post date:** [August 1, 2024, 9:02am UTC](https://forums.unrealengine.com/t/problem-opening-projects/1953713/3 "2024-08-01T09:02:37Z")

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Hey @aleks7kman!

Checking in! Was the above the solution you needed?