# EXCEPTION\_ACCESS\_VIOLATION with LowRankApprox

**URL:** <https://discourse.julialang.org/t/exception-access-violation-with-lowrankapprox/59599>\
**Category:** General Usage\
**Tags:** bug\
**Created:** [April 19, 2021, 4:36pm UTC](https://discourse.julialang.org/t/exception-access-violation-with-lowrankapprox/59599 "2021-04-19T16:36:16Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![BambOoxX](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bambooxx/32/22179_2.png) [@BambOoxX](https://discourse.julialang.org/u/BambOoxX)\
**Post date:** [April 19, 2021, 4:36pm UTC](https://discourse.julialang.org/t/exception-access-violation-with-lowrankapprox/59599/1 "2021-04-19T16:36:16Z")

</div>

While working on some functions based on [LowRankApprox.jl](https://github.com/JuliaMatrices/LowRankApprox.jl#low-rank-factorizations) I got an EXCEPTION\_ACCESS\_VIOLATION error in a MKL dll.

 ![2021-04-19 18_03_33-Window](https://global.discourse-cdn.com/julialang/original/3X/8/3/83e7fbf47a359713279bd4e18848e8030de8782c.png)

Sadly, I was not able to make a MWE from my original code that shows the issue.

My script uses a `pqr` decomposition from LowRankApprox. When I switch back to a standard `qr` the script runs fine.  
Surprisingly, the computation seems to fail once I actually try to access the factors of the QR decomposition with e.g. `F.Q` if the computation was done with `F = pqrfact(A)`

Frankly, I can’t figure how to provide more information about this issue. I’m open to suggestions 🙂

Additional information.

This problem does not show up with julia 1.6.0 with OpenBLAS, so this seems definitely related to MKL