Hard to say anything about this, since it's not always reproducable and most likely database specific, but a possible cause of errors like this are timeouts in the database connection.
If you can find a reproduction pattern (also test with a fresh database), please open a support ticket.
I did finally discover what was causing this error.
When I was updating the "Release Type" of an entire album.
I would see in the status message in the lower right edge saying "Updating Pending Jobs"
In a moment it will count down how many "Jobs" are left to do.
If I initiate another tagging operation before those jobs are done, I will get one of three :
1. The Helium Application will crash.
2. I will get a database read error
3. Get the error shown above
Now that I know that I should wait for all the jobs to be completed before initiating another tagging operation I have not had any issues since.
Patrick Moran
Sorry, an error occured during the operation.
If this error is reproducible, please contact us for further assistance.
*** MESSAGE ***
Could not execute SQL query: UPDATE tblArtists SET IsNew = NULL
This error occurred when I was updating an albums "Release Type"
It has only happened twice so far. ( I had added 30 CD's to my collection)
And
Retrying the operation succeeded.
SO I am posting here more as an FYI than a ticket.