# undefined symbol woes on launch

**URL:** <https://discourse.slicer.org/t/undefined-symbol-woes-on-launch/43782>\
**Category:** Support\
**Created:** [July 20, 2025, 12:55pm UTC](https://discourse.slicer.org/t/undefined-symbol-woes-on-launch/43782 "2025-07-20T12:55:13Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Daniel\_Drucker](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/daniel_drucker/32/80668_2.png) [@Daniel\_Drucker](https://discourse.slicer.org/u/Daniel_Drucker)\
**Post date:** [July 20, 2025, 12:55pm UTC](https://discourse.slicer.org/t/undefined-symbol-woes-on-launch/43782/1 "2025-07-20T12:55:13Z")

</div>

I’m trying to run ./Slicer (in 5.8.1) on RHEL8.9.  
I get:

```auto
$ ./Slicer
/home/ddrucker/Slicer-5.8.1/bin/SlicerApp-real: symbol lookup error: /lib64/libk5crypto.so.3: undefined symbol: EVP_KDF_ctrl, version OPENSSL_1_1_1b

```

I’ve tried dozens of permutations of setting `LD_LIBRARY_PATH` to various things to no avail.

I can’t change/upgrade/downgrade system libraries on the machine.

Is there a way to run the GUI (with extensions) inside a Singularity container? Or is there a `LD_LIBRARY_PATH` setting I’ve missed?

---

<div class="post-metadata">

**Author:** ![Daniel\_Drucker](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/daniel_drucker/32/80668_2.png) [@Daniel\_Drucker](https://discourse.slicer.org/u/Daniel_Drucker)\
**Post date:** [July 20, 2025, 4:57pm UTC](https://discourse.slicer.org/t/undefined-symbol-woes-on-launch/43782/2 "2025-07-20T16:57:48Z")

</div>

Solved!  
Moving the shipped libraries out of the way fixed it:

```auto
mv lib/Slicer-5.8/libcrypto.so.1.1 lib/Slicer-5.8/libcrypto.so.1.1.bak
mv lib/Slicer-5.8/libssl.so.1.1 lib/Slicer-5.8/libssl.so.1.1.bak

```