# Screen freezes up when open some pdf files in the viewer

**URL:** <https://pdfjs.community/t/screen-freezes-up-when-open-some-pdf-files-in-the-viewer/3302>\
**Category:** Technical Support\
**Tags:** pdfjs-express\
**Created:** [May 29, 2024, 8:48pm UTC](https://pdfjs.community/t/screen-freezes-up-when-open-some-pdf-files-in-the-viewer/3302 "2024-05-29T20:48:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![yzhang](https://avatars.discourse-cdn.com/v4/letter/y/87869e/32.png) [@yzhang](https://pdfjs.community/u/yzhang)\
**Post date:** [May 29, 2024, 8:48pm UTC](https://pdfjs.community/t/screen-freezes-up-when-open-some-pdf-files-in-the-viewer/3302/1 "2024-05-29T20:48:12Z")

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**Which product are you using?**  
PDF.js Express Viewer

**PDF.js Express Version**  
|UI version|‘8.7.0’|  
|Core version|‘8.7.4’|  
|webviewer.min.js|‘8.7.4’|

**Detailed description of issue**  
The application freezes up when opening a pdf in the viewer. It’s because the regex test is stuck

 ![image](https://canada1.discourse-cdn.com/flex031/uploads/pdfjscommunity/original/2X/f/f5869d6186ed4a4a34dac1c68fdf88aa295d9a04.png)

**Expected behaviour**  
{Provide a screenshot or description of the expected behaviour}

**Does your issue happen with every document, or just one?**  
Not with every documents, but it happens to many documents

**Link to document**  
{Provide a link to the document in question if possible}

**Code snippet**  
{Provide a relevant code snippet}

---

<div class="post-metadata">

**Author:** ![darian.chen](https://avatars.discourse-cdn.com/v4/letter/d/3d9bf3/32.png) [@darian.chen](https://pdfjs.community/u/darian.chen)\
**Post date:** [May 30, 2024, 2:40pm UTC](https://pdfjs.community/t/screen-freezes-up-when-open-some-pdf-files-in-the-viewer/3302/3 "2024-05-30T14:40:57Z")

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Hi there,

Could you provide the documents that cause this issue?

Best Regards,  
Darian