The Task Scheduler is a snap-in that runs through the MMC (Microsoft Management Console) which enables you to automatically perform routine tasks on a chosen computer. When you create a task on the task scheduler it will generate a file that gets created under your OS drive (normally C:\) C:\Windows\System32\Tasks – and it also generates a registry under the following registry address HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\. If the task is under a folder, it will also create a registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\
At the moment of opening the Task Scheduler MMC, Windows will sync the registry with the files that are located under the Tasks folder, and if it’s not able to match one, then the error message “The selected task {} no longer exists. To see the current tasks, click refresh” will appear.
To resolve this issue, we need to either delete all of the tasks, or locate the corrupt one and delete it.
The easiest way would be to create a new account, since it will delete all tasks.
Method 1: Creating a new user account
Go to Action center and click All Settings and go to Accounts
Go to Family & other users, click Add someone else to this PC.
If you are looking to have a Microsoft account linked to your E-Mail, input your E-Mail. If you wish to have a Local account:
Click on I don’t have this person sign in information.
Select Add a User without a Microsoft Account and input your information.
However, if you have several tasks, and you would like to avoid losing them, then you might need to determine which task is causing the conflict. To do so, you will need to compare both the registry and the task folder.
Method 2: Locate in the task scheduler the corrupt task and delete it from the task file folder
Open Task Scheduler and click OK when prompted with the error. It may seem like you are receiving the same error over and over, but this is really due to the number of tasks which are broken. Make a note of the number of times you are prompted with the the selected task “{0}” error. This is the number of task files that are out of sync with the registry.
Start with the first folder under Windows tasks (Task Scheduler(Local)\Task Scheduler Library\Microsoft\Windows) and select each folder in turn until you receive the the selected task “{0}” error. This folder contains files that are not in sync with the task scheduler.
Open Windows Explorer and navigate to the tasks file folder (%systemroot%\system32\Tasks\Microsoft\Windows) and find the folder which corresponds to the folder in which you received the error.
For some tasks, you will be able to determine which files need to be deleted by comparing the list in the Task Scheduler with the list of files in Explorer. Some tasks will only have a single file in explorer, or, in one case I had 2 and the first was missing. Once Task Scheduler encounters this error it will no longer display tasks so it makes the job of getting the two in sync a little more difficult. Once you have determined which files exist in the File Folder but do not exist in the Task Scheduler folder, delete those files.
IMPORTANT – Close and Re-Open Task Scheduler. Once the error is encountered, Task Scheduler no longer displays the tasks so you need to close it and restart in order to continue your synchronization effort.
Continue to select folders in Task Scheduler under Windows tasks until you encounter the error again and repeat the process of determining which file exists on the file system, but not in Task Scheduler.
Please note, it is possible that this issue could cause the MMC not to be able to load the Task Scheduler snap-in, showing the following error: MMC has detected an error in a snap-in and will unload it. At this point you won’t be able to determine through the Task Scheduler the name of the task that is causing the issue and you will have to find it manually.
Method 3: Compare tasks from registry and explorer, and delete the ones that don’t match
Open C:\Windows\System32\Tasks
Hold the Windows Key and press R, and type down regedit, or you can also type down regedit on the start menu.
Locate the folder HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\
Copy the name of the task from the Explorer and then search for the name under the \TaskCache\Task and \TaskCache\Tree folder in the registry.
Delete any task from the explorer folder that is not shown in the registry folder mentioned above.
Once you are able to manually delete any missing key and match all tasks, restart your computer.