Find error D126 on a folder after you sorted it by a subject or by a name.

One some folders in your mailbox if you type in a filter field a text to search for mails, you get D126 error.

Alternatively a search returns items that do not match find criteria.

These are steps that invoke the problem:

 

1. Click on any folder that holds few mails.

2. Sort the folder by a subject or by a name, i.e by other field than a date.

3. Type in the filter field some text and search brings the D126 error.

4. You can "fix" the D126 error by reordering mails of that folder again by a date. The D126 goes away but the filter does not work properly, i.e. it returns results that do not match a search criteria.