We're sorry you are having problems with license validation, with a "404" error.....
There has never been a 3 machine LIFETIME license available. Sounds like you bought them from another site that MIS Advertised them as 3 pc license .
Please be sure you are not trying to activate your license on more computers than your license allows. Next:
Please be sure you are entering the correct alphanumeric characters in the correct format.
For example, please be sure not to swap "0" for "O", "1" for "I", "S" for "5", "8" for "B", etc; and be sure not to add extra spaces.
"Old" lifetime licenses have both a Key and an ID, each of which needs to be entered in its own field.
The ID format is most likely XXXXX-XXXXX and the Key format is most likely XXXX-XXXX-XXXX-XXXX
("New" and replacement licenses have just a Key, without an ID.)
There is more information here: How do I activate Malwarebytes Anti-Malware? Next:
If those do not resolve your issue, unfortunately, the only folks who can help with that particular "404" error code are the Support folks at the help desk.
We here at the forum do not have access to the necessary information to resolve such an error.
If you already have a ticket at the Help Desk, please try to be patient. The Help Desk is busy, and they are also assisting users with technical support and malware cleanup cases.
Please do not open multiple tickets there -- doing so will slow down the process and could delay their response to you.
If you do NOT already have a ticket at the Help Desk, you may open one HERE.
Please provide the Help Desk with as much of the following information as possible (but do NOT post this sensitive information here in this forum):
Name of purchaser
Email address of purchaser
Date of purchase
cleverbridge reference number (or details about the seller, if it was NOT malwarebytes online store)
MBAM license ID and Key information
Either way, please be sure to check your spam and junk mail folders, to verify that the emails from the Support team did not land there by mistake.
In the interim, you may wish to perform a CLEAN REINSTALL of MBAM -- the setup wizard will offer a 14-day Trial with the full, premium features, while you sort out the licensing issues. (1 Trial per PC per MBAM program version)
Thanks for your patience and understanding,