Encounter frequent crash for our VR project, assertion failed: key isValid()

We made a VR project linked with steamVR and HTC VIVE pro, and having very frequent crash issue. The project is fine when opening without VR, but it will frequently crash when opening with VR device linked. When crashing, it will report : Assertion failed: key isValid() [File:E:\projectname\UnrealEngine\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp][Line:6291]

We are using steamVR 1.2.10, HTC VIVE pro, and Orion for tracking movement. We tried with OpenVR v1_0_10 and v1_0_16, but they all get the same problem.
The error is random happened, sometimes we can have our vr working fine, but other time it just crash when opening with vr.
Is there anyone has any idea about how to fix it? Thanks.

Hey, any updates since then?

Having the same issue, would like to know if you found a solution. Happens in 4.24

The solution in this post worked for me. https://answers.unrealengine.com/questions/971201/ue-4251-crash-on-motion-controller-press.html. I actually ended up replacing the Defaultinput.ini with the one from a newly created VR Blueprint project of the appropriate version (4.26 for me).