Workspace configuration is damaged

Problem

ETS does not start or other error messages similar to the one below are shown:

2023-04-03 14:48:02,961 [1] ERROR System.Windows.Application - System.ArgumentNullException: Der Wert darf nicht NULL sein.Parametername: keybei System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)bei System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)bei System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector)bei Knx.Ets.ObjectModel.Operations.GroupRanges.DeleteGroupRangeOperation..ctor(IEnumerable`1 ranges, Action`1 progress)bei Knx.Ets.ViewModel.Application.Workspace.OperationFactory.CreateDeleteOperation(IEnumerable`1 items, Action`1 callback)bei Knx.Ets.ViewModel.ContextMenu.ContextMenuViewModel.<>c__DisplayClass163_0.<OnDelete>b__0(Action`1 action)bei Knx.Ets.ViewModel.Application.Wizards.GenericWizardPageVM..ctor(String wizardId, Func`2 getOperations, Func`2 getSubtitle, WizardPageAttachment attachment)bei Knx.Ets.ViewModel.Application.Wizards.GenericWizardViewModel..ctor(IList`1 objects)bei Knx.Ets.ViewModel.IocModule.<>c.<Load>b__0_39(Object[] objects)bei Knx.Ets.ViewModel.Tools.WizardDialogService.GetWizard(Object[] values)bei Knx.Ets.ViewModel.Tools.WizardDialogService.ShowGeneric(Boolean withDelay, Object[] values)bei Knx.Ets.ViewModel.Service.ProgressDialogService.ShowDialog(WizardSubtype wizardSubtype, Func`2 getOperationsWithCallback, Action`1 whenFinishedCallback, String localizedDescription, Boolean useDelay)bei Knx.Ets.ViewModel.ContextMenu.ContextMenuViewModel.OnDelete()

Cause

The workspace configuration file is damaged and ETS cannot process it.

Solution

1. Close ETS (if it's open).
2. Locate the project's folder in the project store folder.
3. Note down the project's folder name (i.e. P-ABCD, where ABCD is the project ID).
4. Browse to the folder '%localappdata%\KNX\ETS6\Workspaces' (copy the content within the ' ' to Windows File Explorer).
5. Find and delete the file 'P-ABCD.workspace', where P-ABCD is the project's ID.
6. Start ETS again.