From be5fc0877fbae71b8a993bc6e3c7c2416776629c Mon Sep 17 00:00:00 2001
From: jClugstor <jadonclugston@gmail.com>
Date: Wed, 27 Nov 2024 14:57:21 -0500
Subject: [PATCH] densify sparse W for inv

---
 lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl b/lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl
index 233f45f5bd..ad507a091b 100644
--- a/lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl
+++ b/lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl
@@ -17,7 +17,8 @@ struct StaticWOperator{isinv, T, F} <: AbstractSciMLOperator{T}
         # when constructing W for the first time for the type
         # inv(W) can be singular
         _W = if isinv && callinv
-            inv(W)
+            # W may be sparse, needs to be dense to inv
+            inv(Matrix(W))
         else
             W
         end