diff --git a/examples/controlplane/2a_cnc_interactive.jl b/examples/controlplane/2a_cnc_interactive.jl
index 43595067..19f14c35 100644
--- a/examples/controlplane/2a_cnc_interactive.jl
+++ b/examples/controlplane/2a_cnc_interactive.jl
@@ -1,6 +1,6 @@
 include("setup.jl")
 
-controller = Controller(sim, net, 6, zeros(8,8))
+controller = Controller(sim, net, 6, fill(nothing, 8, 8))
 @process controller()
 
 req_gen = RequestGenerator(sim, net, 1, 8, 6)
diff --git a/src/ProtocolZoo/ProtocolZoo.jl b/src/ProtocolZoo/ProtocolZoo.jl
index 5d35d1b3..a450b040 100644
--- a/src/ProtocolZoo/ProtocolZoo.jl
+++ b/src/ProtocolZoo/ProtocolZoo.jl
@@ -428,7 +428,7 @@ end
                 error("`EntanglementTracker` on node $(prot.node) received a message $(msg) that it does not know how to handle (due to the absence of corresponding `EntanglementCounterpart` or `EntanglementHistory` or `EntanglementDelete` tags). This might have happened due to `CutoffProt` deleting qubits while swaps are happening. Make sure that the retention times in `CutoffProt` are sufficiently larger than the `agelimit` in `SwapperProt`. Otherwise, this is a bug in the protocol and should not happen -- please report an issue at QuantumSavory's repository.")
             end
         end
-        # @debug "EntanglementTracker @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
+        @debug "EntanglementTracker @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
         @yield wait(mb)
         @debug "EntanglementTracker @$(prot.node): Message wait ends at $(now(prot.sim))"
     end
@@ -547,7 +547,7 @@ end
                 end
             end
         end
-        # @debug "RequestTracker @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
+        @debug "RequestTracker @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
         @yield wait(mb)
         @debug "RequestTracker @$(prot.node): Message wait ends at $(now(prot.sim))"
     end
diff --git a/src/ProtocolZoo/controllers.jl b/src/ProtocolZoo/controllers.jl
index 2f0d9e2c..cf73f7a2 100644
--- a/src/ProtocolZoo/controllers.jl
+++ b/src/ProtocolZoo/controllers.jl
@@ -72,7 +72,7 @@ See also [`RequestGenerator`](@ref), [`RequestTracker`](@ref)
     """The node in the network where the control protocol is physically located, ideally a centrally located node"""
     node::Int
     """A matrix for the object containing physical graph metadata for the network"""
-    path_mat::Matrix{Union{Float64, PathMetadata}}
+    path_mat::Matrix{Union{Nothing, PathMetadata}}
 end
 
 @resumable function (prot::Controller)()
@@ -84,7 +84,7 @@ end
             msg = querydelete!(mb, DistributionRequest, ❓, ❓)
             if !isnothing(msg)
                 (msg_src, (_, src, dst)) = msg
-                if typeof(prot.path_mat[src, dst]) <: Number
+                if isnothing(prot.path_mat[src, dst])
                     prot.path_mat[src, dst] = PathMetadata(prot.net.graph, src, dst, Int(length(prot.net[1].staterefs)/2))
                 end
                 path_id = path_selection(prot.sim, prot.path_mat[src, dst])
@@ -113,7 +113,7 @@ end
                     end
                 end
             end
-            # @debug "Controller @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
+            @debug "Controller @$(prot.node): Starting message wait at $(now(prot.sim)) with MessageBuffer containing: $(mb.buffer)"
             @yield wait(mb)
             @debug "Controller @$(prot.node): Message wait ends at $(now(prot.sim))"
         end