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msgFilterRules.dat cannot be read, v24.4 & 24.5 on W7x86 all filtering fails

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I have recent problems with Message Filtering failing. Numerous times I have saved xxx.default profile, uninstalled 24.4(tried updating to 24.5 but no benefit) Downloaded a fresh copy of 24.4, installed, restored the contents of xxx.default profile to newly created profile, overwriting same file names(all as per Profiles support info) Tested Filtering by sending emails from another computer, all works ok, then 3 -4 filters, error message - "Your filters did not work because the msgFilterRules.dat file which contains your filters, could not be read. A new msgFilterRules.dat file will be created and a backup of the old file, called rulesbackup.dat will be created in the same directory" The new msgFilterRules.dat file is of course empty, requiring all the filters to be re-entered after each failure. I would appreciate any assistance, that can be provided.

I have recent problems with Message Filtering failing. Numerous times I have saved xxx.default profile, uninstalled 24.4(tried updating to 24.5 but no benefit) Downloaded a fresh copy of 24.4, installed, restored the contents of xxx.default profile to newly created profile, overwriting same file names(all as per Profiles support info) Tested Filtering by sending emails from another computer, all works ok, then 3 -4 filters, error message - "Your filters did not work because the msgFilterRules.dat file which contains your filters, could not be read. A new msgFilterRules.dat file will be created and a backup of the old file, called rulesbackup.dat will be created in the same directory" The new msgFilterRules.dat file is of course empty, requiring all the filters to be re-entered after each failure. I would appreciate any assistance, that can be provided.

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Try preventing your anti virus program from scanning those folders. Also look in the renamed file... they are text files after all. Is it corrupt, or could Thunderbird simply not open it because another process such as A/V had it locked.

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Matt, Thanks for the advice. The problem was in two parts. 1. msgFilterRules.dat was corrupt, but it wasn't visible. Copied a fresh one from another computer & modified. 2. Excluded msgFilterRules.dat from Avast Now everything back to normal.

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OK, same problem. Except on TBird 24.8.0, running on Mageia 4 Linux. So, obviously AV not an issue. Don't know how to check whether the files are corrupt. Opened it in a text editor, and didn't see anything besides plaintext instructions of some sort. Looks a lot like html without the tags. Tried expanding permissions on the file to include group, and tried setting it executable. Still no joy.

Only thing that occurs to me at this point is perhaps the file is in the wrong group. Anybody know what group(s) this file would ideally need to belong to? It is currently part of my user group, same as the empty msgFilterRules.dat that the program creates in that mail account.

BTW, Is it just me, or does it seem broken that TBird can import from other programs, but can't import something as simple as a filter from its own previous version? I mean, I've been exporting and importing both .json and .html bookmarks around various versions and installations of Firefox for YEARS now, without a hitch. What prevents that sort of thing from being enacted with mail filters in Thunderbird?

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Thank you, thank you, thank you! Just the ticket! Hadn't even known about that add-on's existence! Only part of the add-on's instructions that isn't clear, is that you MUST restart TBird after every filter import. When I tried to put the restart off until last, filters did not import. One at a time, with a restart each time, it worked perfectly! Yay!

Now, if it works on my TBird instance sitting on my old MacBook Pro, I'll be thrilled. Will post again if it works there. Thanks again!

Addendum: Yup. Works on TBird 24.4.0 on a MacBook Pro, running OSX 10.7.5 YAY! THANKS, MATT!

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