Try to ensure that the types are matching in the controller and error estimator.

Author: termi-official

lib/OrdinaryDiffEqCore/src/alg_utils.jl

@@ -380,9 +380,10 @@ function default_controller_v7(QT, alg)
 end
 
 function default_controller_v7(QT, alg::OrdinaryDiffEqCompositeAlgorithm)
-    beta2 = convert(QT, beta2_default(alg.algs[1]))
-    beta1 = convert(QT, beta1_default(alg.algs[1], beta2))
-    return PIController(beta1, beta2)
+    return nothing # This forces a fall-back to the legacy implementation
+    # beta2 = convert(QT, beta2_default(alg.algs[1]))
+    # beta1 = convert(QT, beta1_default(alg.algs[1], beta2))
+    # return PIController(beta1, beta2)
     # TODO Uncomment this code below to when removing the legacy controllers on OrdinaryDiffEq v7.
     # return CompositeController(
     #     __default_controller_v7(QT, alg.algs)

lib/OrdinaryDiffEqCore/src/integrators/controllers.jl

@@ -89,8 +89,10 @@ end
 end
 
 reset_alg_dependent_opts!(controller::AbstractController, alg1, alg2) = nothing
+reset_alg_dependent_opts!(controller::AbstractControllerCache, alg1, alg2) = nothing
 
 SciMLBase.reinit!(integrator::ODEIntegrator, controller::AbstractController) = nothing
+SciMLBase.reinit!(integrator::ODEIntegrator, controller::AbstractControllerCache) = nothing
 
 function post_newton_controller!(integrator, alg)
     return post_newton_controller!(integrator, integrator.opts.controller, alg)
@@ -321,13 +323,15 @@ function step_reject_controller!(integrator, controller::PIController, alg)
     return integrator.dt /= min(inv(qmin), q11 / gamma)
 end
 
-function reset_alg_dependent_opts!(controller::PIController, alg1, alg2)
-    if controller.beta2 == beta2_default(alg1)
-        controller.beta2 = beta2_default(alg2)
+function reset_alg_dependent_opts!(controller::PIController{QT}, alg1, alg2) where {QT}
+    # These guards here prevent potentially that user-defined betas get overridden.
+    if controller.beta2 == QT(beta2_default(alg1))
+        controller.beta2 = QT(beta2_default(alg2))
     end
-    return if controller.beta1 == beta1_default(alg1, controller.beta2)
-        controller.beta1 = beta1_default(alg2, controller.beta2)
+    if controller.beta1 == QT(beta1_default(alg1, controller.beta2))
+        controller.beta1 = QT(beta1_default(alg2, controller.beta2))
     end
+    return nothing
 end
 
 struct NewPIController{T} <: AbstractController

lib/OrdinaryDiffEqCore/src/perform_step/composite_perform_step.jl

@@ -298,4 +298,3 @@ end
 # Example: send the history variables from one multistep method to another
 
 transfer_cache!(integrator, alg1, alg2) = nothing
-reset_alg_dependent_opts!(::Union{AbstractController, AbstractControllerCache}, alg1, alg2) = nothing

lib/OrdinaryDiffEqCore/src/solve.jl

@@ -487,14 +487,6 @@ function SciMLBase.__init(
     end
 
     QT = determine_controller_datatype(u, internalnorm, tspan)
-    EEstT = if tTypeNoUnits <: Integer
-       typeof(qmin)
-    elseif prob isa SciMLBase.AbstractDiscreteProblem
-        # The QT fields are not used for DiscreteProblems
-        constvalue(tTypeNoUnits)
-    else
-        typeof(internalnorm(u, t))
-    end
 
     # The following code provides an upgrade path for users by preserving the old behavior.
     legacy_controller_parameters = (gamma, qmin, qmax, qsteady_min, qsteady_max, beta1, beta2, qoldinit)
@@ -517,6 +509,14 @@ function SciMLBase.__init(
         qoldinit = hasfield(typeof(controller), :qoldinit) ? controller.qoldinit : (anyadaptive(alg) ? 1 // 10^4 : 0)
     end
 
+    EEstT = if tTypeNoUnits <: Integer
+        promote_type(typeof(qmin), typeof(qmax))
+    elseif prob isa SciMLBase.AbstractDiscreteProblem
+        constvalue(tTypeNoUnits)
+    else
+        typeof(internalnorm(u, t))
+    end
+
     atmp = if hasfield(typeof(cache), :atmp)
         cache.atmp
     else