for /f %%a in ('dir /b "%APPDATA%\Thunderbird\Profiles\*.default"') do SET TBPROFILE=%APPDATA%\Thunderbird\Profiles\%%a
IF NOT EXIST "%TBPROFILE%" GOTO :EOF
IF EXIST "%TBPROFILE%\extensions.json" (
  IF NOT EXIST "%TBPROFILE%\extensions.{{ tb_major_version }}.json" (
    rename "%TBPROFILE%\extensions.json" extensions.{{ tb_major_version }}.json
  )
)

IF EXIST "%TBPROFILE%\addonStartup.json.lz4" (
  IF NOT EXIST "%TBPROFILE%\addonStartup.{{ tb_major_version }}.json.lz4" (
    rename "%TBPROFILE%\addonStartup.json.lz4" addonStartup.{{ tb_major_version }}.json.lz4
  )
)