Append not possible with EncryptFilenames

[GitHubSunnyUK]

Firstly, thank you for sharing this script. That's really kind of you!

I have noticed that when using -Format SevenZip -EncryptfileNames, then appending a file to an existing .7z archive gives an error message:

Compress-7Zip : Invalid archive: open/read error! Is it encrypted and a wrong password was provided?
If your archive is an exotic one, it is possible that SevenZipSharp has no signature for its format and thus decided it is TAR by mistake. Message: Can not update the archive: Open() failed.
At line:1 char:1
+ Compress-7Zip -ArchiveFileName test2.7z -Path .\zip.txt -Format Seven ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (SevenZip4PowerS...+CompressWorker:CompressWorker) [Compress-7Zip], SevenZipArchiveException
    + FullyQualifiedErrorId : err01,SevenZip4PowerShell.Compress7Zip

The -Append function seems to work perfectly when the filenames are not encrypted.

Is this something you might be able to have a look at, at some time please.

Kind regards,
Tomas