# Zlib1.dll is missing while testing on Julia 1.5

**URL:** <https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731>\
**Category:** General Usage\
**Created:** [November 7, 2020, 11:15am UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731 "2020-11-07T11:15:09Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![barleyman99](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/barleyman99/32/25697_2.png) [@barleyman99](https://discourse.julialang.org/u/barleyman99)\
**Post date:** [November 7, 2020, 11:15am UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731/1 "2020-11-07T11:15:09Z")

</div>

Today I got an error while testing on my Windows 10 on Julia 1.5. It says that Zlib1.dll is missing. Any quick fix for this?

---

<div class="post-metadata">

**Author:** ![giordano](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/giordano/32/2166_2.png) [@giordano](https://discourse.julialang.org/u/giordano)\
**Post date:** [November 7, 2020, 11:17am UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731/2 "2020-11-07T11:17:40Z")

</div>

Can you please please provide more context and the full stacktrace? Hard to guess what’s happening without further information

---

<div class="post-metadata">

**Author:** ![barleyman99](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/barleyman99/32/25697_2.png) [@barleyman99](https://discourse.julialang.org/u/barleyman99)\
**Post date:** [November 12, 2020, 10:37am UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731/3 "2020-11-12T10:37:51Z")

</div>

@giordano, Thanks for your reply and query. But, I don’t think I need more to explain because I solved it today myself. I upgraded the old graphics drivers and Windows Updates. Then, after googling, I downloaded the missing zlib1.dll from here: [https://dlldownloads.com/zlib1-dll/](https://dlldownloads.com/zlib1-dll/) and placed it into the installation directory. It worked perfectly for me. Thanks once again.

---

<div class="post-metadata">

**Author:** ![kunwarsantosh](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kunwarsantosh/32/28453_2.png) [@kunwarsantosh](https://discourse.julialang.org/u/kunwarsantosh)\
**Post date:** [September 6, 2024, 2:22pm UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731/4 "2024-09-06T14:22:22Z")

</div>

Can you specify which folder did you put the .dll into? I am getting errors while running PDFIO, ERROR: The following package names could not be resolved:

- zlib1 (not found in project, manifest or registry)

---

<div class="post-metadata">

**Author:** ![Monicate](https://avatars.discourse-cdn.com/v4/letter/m/e5b9ba/32.png) [@Monicate](https://discourse.julialang.org/u/Monicate)\
**Post date:** [October 31, 2025, 8:59am UTC](https://discourse.julialang.org/t/zlib1-dll-is-missing-while-testing-on-julia-1-5/49731/5 "2025-10-31T08:59:10Z")

</div>

Hey, I have the same problem, do you remember what installation folder you put it in?