As Paul Randal said these are broken links to statsistics blobs in sysindexes. Unfortunately you cannot delete these with
DROP STATISTICS neither with
DELETE FROM sysindexes as these will bomb out with the same error.
Such broken stats result in
Error: 7105, Severity: 22, State: 6\nPage (1:8439), slot 3 for text, ntext, or image node does not exist.. when
SELECT-ing the column with broken statistics because the engine is trying to access these stats (it's accessing stats for all selected column and NOLOCK does not help).
What I did to prevent the engine from using the broken stats (and be able to export the data from my user tables) was to update
sysindexes.keys column (for all stats) with a bogus (but valid) binary blob like this
SET keys = 0x3800380004000A00000000000000000001000100000000000400010000000000AD01AD0008000000000000000000000000000500000000020000050000000100
WHERE (status & 64) <> 0
The blob value came from
keys value of a statistics on a new table with a single column like
CREATE TABLE aaa(ID INT) and then created stats on
On MSSQL 2000 all of the updates had to be done under
EXEC sp_configure 'allow updates', 1
RECONFIGURE WITH OVERRIDE
. . . with the
MSSQLSERVER service stopped and manually started
C:\MSSQL\Binn\sqlservr.exe -m as a console application.
Another unfortunate fact was that all of this had to be done under MSSQL 2000 because the corrupted DB cannot be upgraded to newer SQL Server version -- the attach/restore failed while accessing the broken statistics. . . Yikes!