diff --git a/src/App/Document.cpp b/src/App/Document.cpp
index fe186f3c41..71ed12bc2e 100644
--- a/src/App/Document.cpp
+++ b/src/App/Document.cpp
@@ -995,7 +995,14 @@ void Document::Save(Base::Writer& writer) const
 
     writer.incInd();
 
+    // NOTE: This differs from LS3 Code. Persisting this table
+    //       forces the assertion in Writer.addFile(...): assert(!isForceXML()); to be removed
+    //       see: https://github.com/FreeCAD/FreeCAD/issues/27489
+    //
+    // Original code in LS3:
+    //       d->Hasher->setPersistenceFileName(0);
     d->Hasher->setPersistenceFileName("StringHasher.Table");
+
     for (const auto o : d->objectArray) {
         o->beforeSave();
     }
@@ -3134,7 +3141,7 @@ DocumentObject* Document::addObject(const char* sType,
                AddObjectOption::SetNewStatus
                    | (isPartial ? AddObjectOption::SetPartialStatus : AddObjectOption::UnsetPartialStatus)
                    | (isNew ? AddObjectOption::DoSetup : AddObjectOption::None)
-                   | AddObjectOption::ActivateObject, 
+                   | AddObjectOption::ActivateObject,
                viewType);
 
     // return the Object
@@ -3201,7 +3208,7 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName, Add
     else {
         ObjectName = getUniqueObjectName(pcObject->getTypeId().getName());
     }
- 
+
     // insert in the name map
     d->objectMap[ObjectName] = pcObject;
     d->objectNameManager.addExactName(ObjectName);
@@ -3217,7 +3224,7 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName, Add
     }
     d->objectIdMap[pcObject->_Id] = pcObject;
     d->objectArray.push_back(pcObject);
-     
+
      // do no transactions if we do a rollback!
     if (!d->rollback) {
         // Undo stuff
@@ -3236,9 +3243,9 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName, Add
     if (!isPerformingTransaction() && options.testFlag(AddObjectOption::DoSetup)) {
         pcObject->setupObject();
     }
- 
+
     if (options.testFlag(AddObjectOption::SetNewStatus)) {
-        pcObject->setStatus(ObjectStatus::New, true);    
+        pcObject->setStatus(ObjectStatus::New, true);
     }
     if (options.testFlag(AddObjectOption::SetPartialStatus) || options.testFlag(AddObjectOption::UnsetPartialStatus)) {
         pcObject->setStatus(ObjectStatus::PartialObject, options.testFlag(AddObjectOption::SetPartialStatus));
@@ -3250,15 +3257,15 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName, Add
     pcObject->_pcViewProviderName = viewType ? viewType : "";
 
     signalNewObject(*pcObject);
- 
+
     // do no transactions if we do a rollback!
     if (!d->rollback && d->activeUndoTransaction) {
         signalTransactionAppend(*pcObject, d->activeUndoTransaction);
     }
- 
+
     if (options.testFlag(AddObjectOption::ActivateObject)) {
         d->activeObject = pcObject;
-        signalActivatedObject(*pcObject);    
+        signalActivatedObject(*pcObject);
     }
 }
 
@@ -3295,7 +3302,7 @@ void Document::_removeObject(DocumentObject* pcObject, RemoveObjectOptions optio
         FC_ERR("Cannot delete " << pcObject->getFullName() << " while recomputing");
         return;
     }
-    
+
     TransactionLocker tlock;
 
     _checkTransaction(pcObject, nullptr, __LINE__);
@@ -3305,7 +3312,7 @@ void Document::_removeObject(DocumentObject* pcObject, RemoveObjectOptions optio
         FC_ERR("Internal error, could not find " << pcObject->getFullName() << " to remove");
     }
 
-    if (options.testFlag(RemoveObjectOption::PreserveChildrenVisibility) 
+    if (options.testFlag(RemoveObjectOption::PreserveChildrenVisibility)
         && !d->rollback && d->activeUndoTransaction && pcObject->hasChildElement()) {
         // Preserve link group sub object global visibilities. Normally those
         // claimed object should be hidden in global coordinate space. However,
@@ -3313,7 +3320,7 @@ void Document::_removeObject(DocumentObject* pcObject, RemoveObjectOptions optio
         // children, which may now in the global space. When the parent is
         // undeleted, having its children shown in both the local and global
         // coordinate space is very confusing. Hence, we preserve the visibility
-        // here        
+        // here
         for (auto& sub : pcObject->getSubObjects()) {
             if (sub.empty()) {
                 continue;
@@ -3360,7 +3367,7 @@ void Document::_removeObject(DocumentObject* pcObject, RemoveObjectOptions optio
     }
 
     std::unique_ptr<DocumentObject> tobedestroyed;
-    if ((options.testFlag(RemoveObjectOption::MayDestroyOutOfTransaction) && !d->rollback && !d->activeUndoTransaction) 
+    if ((options.testFlag(RemoveObjectOption::MayDestroyOutOfTransaction) && !d->rollback && !d->activeUndoTransaction)
         || (options.testFlag(RemoveObjectOption::DestroyOnRollback) && d->rollback)) {
         // if not saved in undo -> delete object later
         std::unique_ptr<DocumentObject> delobj(pos->second);
@@ -3376,13 +3383,13 @@ void Document::_removeObject(DocumentObject* pcObject, RemoveObjectOptions optio
             break;
         }
     }
-    
+
     // In case the object gets deleted the pointer must be nullified
     if (tobedestroyed) {
         tobedestroyed->pcNameInDocument = nullptr;
     }
 
-    // Erase last to avoid invalidating pcObject->pcNameInDocument 
+    // Erase last to avoid invalidating pcObject->pcNameInDocument
     // when it is still needed in Transaction::addObjectNew
     d->objectMap.erase(pos);
 }
diff --git a/src/Base/Writer.cpp b/src/Base/Writer.cpp
index 90f0445891..44ead1e313 100644
--- a/src/Base/Writer.cpp
+++ b/src/Base/Writer.cpp
@@ -294,7 +294,8 @@ std::vector<std::string> Writer::getErrors() const
 std::string Writer::addFile(const char* Name, const Base::Persistence* Object)
 {
     // always check isForceXML() before requesting a file!
-    assert(!isForceXML());
+    // assert(!isForceXML()); Changes introduced in 1.0 differ from LS3 (TNP), so this assertion is
+    // not valid anymore.
 
     FileEntry temp;
     temp.FileName = Name ? Name : "";