diff --git a/matRad/bioModels/matRad_BiologicalModel.m b/matRad/bioModels/matRad_BiologicalModel.m
index b770dd9b4..cfd18ddec 100644
--- a/matRad/bioModels/matRad_BiologicalModel.m
+++ b/matRad/bioModels/matRad_BiologicalModel.m
@@ -128,6 +128,13 @@
             folders = [folders matRad_cfg.userfolders];
 
             persistent metaBioModels lastOptionalPaths
+            
+            %First we do a sanity check if persistently stored metaclasses are valid
+            if ~matRad_cfg.isOctave && ~isempty(metaBioModels) && ~all(cellfun(@isvalid,metaBioModels))
+                matRad_cfg.dispWarning('Found invalid BioModels, updating model cache.');
+                metaBioModels = [];
+            end
+
             if isempty(metaBioModels) || (~isempty(lastOptionalPaths) && ~isequal(lastOptionalPaths, folders))
                 lastOptionalPaths = folders;
                 metaBioModels = matRad_findSubclasses(meta.class.fromName(mfilename('class')),'folders',folders,'includeSubfolders',true);
diff --git a/matRad/doseCalc/+DoseEngines/@matRad_DoseEngineBase/getAvailableEngines.m b/matRad/doseCalc/+DoseEngines/@matRad_DoseEngineBase/getAvailableEngines.m
index 445b5b79d..44582f171 100644
--- a/matRad/doseCalc/+DoseEngines/@matRad_DoseEngineBase/getAvailableEngines.m
+++ b/matRad/doseCalc/+DoseEngines/@matRad_DoseEngineBase/getAvailableEngines.m
@@ -37,6 +37,14 @@
 %Get available, valid classes through call to matRad helper function
 %for finding subclasses
 persistent allAvailableDoseEngines lastOptionalPaths
+
+%First we do a sanity check if persistently stored metaclasses are valid
+if ~matRad_cfg.isOctave && ~isempty(allAvailableDoseEngines) && ~all(cellfun(@isvalid,allAvailableDoseEngines))
+    matRad_cfg.dispWarning('Found invalid Dose Engines, updating engine cache.');
+    allAvailableDoseEngines = [];
+end
+
+%Check if we need to find the engines and if yes, do
 if isempty(allAvailableDoseEngines) || (~isempty(lastOptionalPaths) && ~isequal(lastOptionalPaths, optionalPaths))
     lastOptionalPaths = optionalPaths;
     allAvailableDoseEngines = matRad_findSubclasses('DoseEngines.matRad_DoseEngineBase','packages',{'DoseEngines'},'folders',optionalPaths,'includeAbstract',false);
diff --git a/matRad/scenarios/matRad_ScenarioModel.m b/matRad/scenarios/matRad_ScenarioModel.m
index 640ed52c4..f84a3dfc3 100644
--- a/matRad/scenarios/matRad_ScenarioModel.m
+++ b/matRad/scenarios/matRad_ScenarioModel.m
@@ -234,6 +234,13 @@ function listAllScenarios(this)
             folders = [folders matRad_cfg.userfolders];
 
             persistent metaScenarioModels lastOptionalPaths
+            
+            %First we do a sanity check if persistently stored metaclasses are valid
+            if ~matRad_cfg.isOctave && ~isempty(metaScenarioModels) && ~all(cellfun(@isvalid,metaScenarioModels))
+                matRad_cfg.dispWarning('Found invalid ScenarioModels, updating model cache.');
+                metaScenarioModels = [];
+            end
+
             if isempty(metaScenarioModels) || (~isempty(lastOptionalPaths) && ~isequal(lastOptionalPaths, folders))
                 lastOptionalPaths = folders;
                 metaScenarioModels = matRad_findSubclasses(meta.class.fromName(mfilename('class')),'folders',folders,'includeSubfolders',true);
diff --git a/matRad/steering/matRad_StfGeneratorBase.m b/matRad/steering/matRad_StfGeneratorBase.m
index 1f48daf88..31c5a11ee 100644
--- a/matRad/steering/matRad_StfGeneratorBase.m
+++ b/matRad/steering/matRad_StfGeneratorBase.m
@@ -446,6 +446,13 @@ function createPatientGeometry(this)
             %Get available, valid classes through call to matRad helper function
             %for finding subclasses
             persistent allAvailableStfGenerators lastOptionalPaths
+            
+            %First we do a sanity check if persistently stored metaclasses are valid
+            if ~matRad_cfg.isOctave && ~isempty(allAvailableStfGenerators) && ~all(cellfun(@isvalid,allAvailableStfGenerators))
+                matRad_cfg.dispWarning('Found invalid Steering Geometry Generators, updating cache.');
+                allAvailableStfGenerators = [];
+            end
+
             if isempty(allAvailableStfGenerators) || (~isempty(lastOptionalPaths) && ~isequal(lastOptionalPaths, optionalPaths))
                 lastOptionalPaths = optionalPaths;
                 allAvailableStfGenerators = matRad_findSubclasses(mfilename('class'),'folders',optionalPaths,'includeAbstract',false);