Are LibreOffice 4.1.5 installer and help files valid when digital signature checks fail?

For both “LibreOffice_4.1.5_Win_x86.msi” and “LibreOffice_4.1.5_Win_x86_helppack_en-US.msi” files, the digital signature check failed with the following message.

“A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file.”

Are the files valid?

Thank you.

What is your system clock? Is it OK or you were playing around with computer clock.
Where did you download LibreOffice files from?

Thank you for your reply.

My system clock is accurate.

Downloaded the LibreOffice 4.1.5 installer and help files from the “LibreOffice Stable” webpage at

Successfully verified digital signatures for different programs from a different vendor downloaded less than an hour before the LibreOffice files.

The “Certificate Information” for both LibreOffice files states the following.

"This certificate has expired or is not yet valid.

Issued to: The Document Foundation

Issued by: StartCom Class 2 Primary Intermediate Object CA

Valid from 2012-04-10 to 2014-04-11"

I downloaded and checked the digital signature for both files on 2014-04-28, so the certificates for both expired before I downloaded them.

I cannot give you an answer but this is probably a workaround:

I download all my LibO version from:
All downloads I made were safe and expect them always to be save from the mentioned source.

Thank you for your reply.

Please note my reply to comment by L-user above.