I cant open received pdf invoice signed by a valid certificate.
In every other client everything works just fine except in eMclient (version 8.1.876).
Error is: Signature Decoding Failure
Signiture validation: The message hash differs from the signature value.
What happens if you save the attachment, then open it from Windows Explorer?
Story is the same. Size of saved atachment is to small and it can not be opened.
Is it possible that the file was corrupt when sent? Can you try opening it from the web interface for your email provider?
No, the file is just fine.
I can open it normally in mails web interface or any other mail client I tested.
The problem first appeared at the end of july. The last invoice I could open was received ath end of June signed with the same certificate.
If you go to Menu > Settings > General and tick Show Local Folders, then copy the affected message to your Local Folder Inbox, can you view the attachment from there?
Nope. I got same error also in my local folder.
Who is your email provider?
My email provider is GMAIL.
In eM Client, right-click on the All Mail folder and choose Properties > Repair. This will resync the contents of the IMAP folders with the server.
Once the repair is complete, try opening the attachment again.
OK. Now it works. Thank you. Will this issue persist in future? Will I have to repair this folder over and over again?
The message cache became corrupted for some reason, but because the messages are still on the server, the repair was able to recache them. It shouldn’t happen regularly, but at least now you know how to fix it if it happens again.