Mozzilla Thunderbird creating popstate-1.dat folders when KTS active

  • 13 November 2019
  • 4 replies

I have an issue which I am unable to solve.

When I have KTS active and start Thunderbird it generates multiple popstate-1(and 2, 3 4 etc).dat and msgFilterRules-1(2, 3,4 etc).dat folders. It will often download messages multiple times.

I also cannot send emails when KTS is active

When I turn off protection I do not get the problems.

Any advice on how to prevent this would be greatly appreciated.


KTS version €

Thunderbird 60.9.1 (32-bit)

OS Name    Microsoft Windows 10 Pro
Version    10.0.17763 Build 17763
System Model    Surface Pro
System Type    x64-based PC



4 replies

Userlevel 7
Badge +5


There are two possible courses of action. One is to post your GetSystemInfo report here, so forum users can help, or the other is to Contact Tech Support. 

1. Please post your GetSystemInfo report link, instructions: https://support.kaspersky.com/common/diagnostics/3632
  Please upload the GetSystemInfo zip folder that is inside the larger GSI zip to the GSI parser site http://www.getsysteminfo.com/ and post the url to the parsed report here, in your next post.

2. Or, please contact Tech Support: https://my.kaspersky.com/support/

Please attach the following items to your Tech Support request: 

a. Description of the issue.
b. Screenshot, as needed.
c. GSI

Userlevel 7
Badge +11

Hello @MPBurr,

Additional to @richbuff:bow_tone3:

:one: In KTS, Network Settings, Mozilla Firefox & Thiunderbird, which certificate store is selected?

:two:  Exit Thunderbird.

:three:  Open KTS, Threats &  Exclusions, Manage Exclusions: try adding an exclusion for Thunderbird Profile folder, the path is:

C:\Users\YOURNAME\AppData\Local\Thunderbird\Profiles\i0soxgur.default\ < note, your  .default folder may have a unique name, not necessarily i0soxgur 


:four:  Shutdown PC using Full Shutdown, not Restart.

:five:  Start PC, login.

:six:  Start KTS, run a manual Database Update - allow it to complete.

:seven:  Start Thunderbird, recheck  “Thunderbird  generates multiple .dat” folders issue?

:eight:  Check Thunderbird email send issue?

Please let us know?

Thank you. 


Thank you richbuff and FLOOD for the replies, I will do the above when I get some time and let you know how I go.


Userlevel 7
Badge +11

Hello @MPBurr,

Thank you for posting back.

  1. If “adding an exclusion” doesn’t work, try changing the certificate store for Mozilla Firefox & Thunderbird, to do that, it’s necessary to export  Kaspersky Anti-Virus Personal Root Certificate, then import the certificate, the “help” link is missing some info, see post by   @TomFiii ​​​​​​, I’ve documented the complete export process. 

:octagonal_sign: The last option would be to “deselect” Scan secure traffic in Mozilla applications, however, if that actually resolves either the .dat folder creation & or the “send” issue, or both, you must contact Kaspersky Lab please, bc, (imo) deselecting Mozilla SST is a “workaround”, not a fix:thinking::octagonal_sign:

Please let us know if anything works and or if you escalate to the Lab?

Thank you:pray_tone3: