Error message I haven't been able to figure out. Help, please?

I am so sorry to be posting this a third time, but my first two
postings have not generated any suggestion on how to stop this message
from coming up.

Does anyone have any idea how to keep it from happening and how to get
the newsgroup to remember the kill filters I have installed in a
particular newsgroup? I have not had the problem in any of the others.

Thank you all for all the help you have given me through the years.

Here is the message"

Your filters do not work because the msgFilterRules.dat file, which
contains you filters, could not be read.
A new msgFilterRules.dat file will be creted and a backup of the old
file, called rules backup.dat will be created in the same directory.

 

You had set up some message rules in your browser.
The file that stored those rules became corrupt (could not
be read).
So that .dat file was `backed up`, and a new empty .dat
file was created.
That means that, at the moment you have no filter rules.
So you`ll have to create new rules.

 

<par order rearranged>

That file is a Tbird file with your message rules. Apparently it is
corrupt/b0rken.

Likely you are going to have to re-create your message rules to get an
intact .dat file. One place advises changing the filename to
backup.dat.

http://kb.mozillazine.org/Filters_(Thunderbird) The file that stores
your filter settings in called "msgFilterRules.dat". Each account will
have its own "msgFilterRules.dat" file, stored in the account subfolder
in the "Mail" or "ImapMail" folder in your profile folder. (In the case
of filters for Local Folders, "msgFilterRules.dat" will be found inside
the "Local Folders" folder itself.)

.... then follows some strategies for using one account's .dat file for
another account.

 

The error message is just about as clear as one can be. It tells
you want is happening and where. It tells you want the filenames,
new and old, are. But if this is happening every time you run
Thunderbird, I haven't been able to find anything in why that
would be happening consistently; i.e., why the new
msgFilterRules.dat that it made last time would be corrupt the
next time you ran the program. So I'd suggest that your next step
might be checking in at mozilla.support.thunderbird at their
server news.mozilla.org.

(Info at http://www.mozilla.org/support/#newsgroups)

 

Thank you meerkat, Mike Easter and Blinky.
I have printed out all of your suggestions and they should take me
down the right path. I couldn't figure out why the same thing has not
happened in the other newsgroups I subscribe to using Thunderbird.

I know I will always get helpful suggestions here when I pose my
question in an understandable way.