Anchor Based is not working to extract information for the variable

And If i am using the Get OCR text activity to extract the value, It works for first document which i have tagged and while reading the value from other document,it throws an error :-1:
UiPath.Core.SelectorNotFoundException: Could not find the UI element corresponding to this selector:
[1]
[2]
[3]
[4]

Search failed at selector tag:
[4]

The closest matches found are:
[79%]
[50%] at UiPath.Core.Activities.ScopeActivity.OnFaulted(NativeActivityFaultContext faultContext, Exception propagatedException, ActivityInstance propagatedFrom)
at System.Activities.Runtime.FaultCallbackWrapper.FaultWorkItem.Execute(ActivityExecutor executor, BookmarkManager bookmarkManager)

Kindly help me .

Best Regards,
Rahul