Object reference not set to an instance of an object error on loading apply changes

I am getting the error called Object reference not set to an instance of an object on apply changes

below is the message which I get  have pasted.

what can be actual the issue?

Feedback Type:
Frown (Error)

Error Message:
Object reference not set to an instance of an object.Stack Trace Message:
Object reference not set to an instance of an object.

PowerBINonFatalError:
{"AppName":"PBIDesktop","AppVersion":"2.87.762.0","ModuleName":"Microsoft.PowerBI.Modeler.dll","Component":"Microsoft.PowerBI.Modeler.DateTableSubsystem","Error":"System.NullReferenceException","MethodDef":"CreateLocalDateTable","ErrorOffset":"136"}

Snapshot Trace Logs:
C:\Users\sheetals\AppData\Local\Microsoft\Power BI Desktop\FrownSnapShota9be32f5-17bf-4abd-a1fb-d33a3be74ae4.zip

Model Default Mode:
Import

Model Version:
PowerBI_V3

Is Report V3 Models Enabled:
True

Performance Trace Logs:
C:\Users\sheetals\AppData\Local\Microsoft\Power BI Desktop\PerformanceTraces.zip

Enabled Preview Features:
PBI_shapeMapVisualEnabled
PBI_SpanishLinguisticsEnabled
PBI_NewWebTableInference
PBI_qnaLiveConnect
PBI_v3ModelsPreview

Disabled Preview Features:
PBI_JsonTableInference
PBI_ImportTextByExample
PBI_ExcelTableInference
PBI_azureMapVisual
PBI_dataPointLassoSelect
PBI_narrativeTextBox
PBI_dynamicParameters
PBI_anomalyDetection
PBI_newFieldList

Disabled DirectQuery Options:
TreatHanaAsRelationalSource

Cloud:
GlobalCloud

ModelChangeStartingStackTrace:
at System.Environment.GetStackTrace(Exception e, Boolean needFileInfo)
at System.Environment.get_StackTrace()
at Microsoft.PowerBI.Modeling.Engine.Authoring.AsyncModelAuthoringService.RunExtendedModelChangeAsync(Action`1 extendedModelChange, ModelingSession modelingSession, ModelingMashupDocument mashupDocument, IModelAuthoringChangeScopeProvider changeScopeProvider, Boolean roleChangesImpactQueries, IRefreshPolicyUpdater refreshPolicyUpdater, CancellationToken cancellationToken)
at Microsoft.PowerBI.Modeling.Engine.Loader.PowerQueryToModelLoader.PerformLoadInternal(IRelationshipLoader relationshipLoader, IModelAuthoringChangeScopeProvider authoringChangeScopeProvider, IModelingQueryServices queryServices, Action`1 beforeSchemaSyncCallback, Action`1 afterSchemaSyncCallback, IRefreshPolicyUpdater refreshPolicyUpdater, Boolean skipImpactAnalysisWarning)
at Microsoft.PowerBI.Modeling.Engine.Loader.PowerQueryToModelLoader.<>c__DisplayClass18_0.<PerformLoadAsync>b__1()
at System.Threading.Tasks.Task`1.InnerInvoke()
at System.Threading.Tasks.Task.Execute()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
at System.Threading.Tasks.Task.ExecuteEntry(Boolean bPreventDoubleExecution)
at System.Threading.ThreadPoolWorkQueue.Dispatch()

PowerBIUserFeedbackServices_IsReported:
True

Formulas:

section Section1;

shared #"ORDER_ITEMS" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"ORDER_ITEMS1" = OT{[Name="ORDER_ITEMS"]}[Data],
#"Merged Queries ORDER_ITEMS_ORDER_ID9" = Table.NestedJoin(#"ORDER_ITEMS1", {"ORDER_ID"}, ORDERS, {"ORDER_ID"}, "ORDERS", JoinKind.Inner),
#"Expanded ORDERS 9" = Table.ExpandTableColumn(#"Merged Queries ORDER_ITEMS_ORDER_ID9", "ORDERS", {"ORDER_ID","CUSTOMER_ID","STATUS","SALESMAN_ID","ORDER_DATE"},{"ORDER_ID (ORDERS)","CUSTOMER_ID","STATUS","SALESMAN_ID","ORDER_DATE"}),
#"Merged Queries ORDER_ITEMS_CUSTOMER_ID30" = Table.NestedJoin(#"Expanded ORDERS 9", {"CUSTOMER_ID"}, CUSTOMERS, {"CUSTOMER_ID"}, "CUSTOMERS", JoinKind.Inner),
#"Expanded CUSTOMERS 30" = Table.ExpandTableColumn(#"Merged Queries ORDER_ITEMS_CUSTOMER_ID30", "CUSTOMERS", {"CUSTOMER_ID","NAME","ADDRESS","WEBSITE","CREDIT_LIMIT"},{"CUSTOMER_ID (CUSTOMERS)","NAME","ADDRESS","WEBSITE","CREDIT_LIMIT"}),
#"Merged Queries ORDER_ITEMS_CUSTOMER_ID2" = Table.NestedJoin(#"Expanded CUSTOMERS 30", {"CUSTOMER_ID"}, CONTACTS, {"CUSTOMER_ID"}, "CONTACTS", JoinKind.Inner),
#"Expanded CONTACTS 2" = Table.ExpandTableColumn(#"Merged Queries ORDER_ITEMS_CUSTOMER_ID2", "CONTACTS", {"CONTACT_ID","FIRST_NAME","LAST_NAME","EMAIL","PHONE","CUSTOMER_ID"},{"CONTACT_ID","FIRST_NAME","LAST_NAME","EMAIL","PHONE","CUSTOMER_ID (CONTACTS)"})
in
#"Expanded CONTACTS 2";

shared #"ORDERS" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"ORDERS1" = OT{[Name="ORDERS"]}[Data]
in
#"ORDERS1";

shared #"CUSTOMERS" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"CUSTOMERS1" = OT{[Name="CUSTOMERS"]}[Data]
in
#"CUSTOMERS1";

shared #"CONTACTS" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"CONTACTS1" = OT{[Name="CONTACTS"]}[Data]
in
#"CONTACTS1";

shared #"PRODUCTS" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"PRODUCTS1" = OT{[Name="PRODUCTS"]}[Data]
in
#"PRODUCTS1";

shared #"PRODUCT_CATEGORIES" = let
#"Source" = Oracle.Database("(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=orcl)))", [HierarchicalNavigation=true ]),
OT = #"Source"{[Schema="OT"]}[Data],
#"PRODUCT_CATEGORIES1" = OT{[Name="PRODUCT_CATEGORIES"]}[Data]
in
#"PRODUCT_CATEGORIES1";