MBAM 2.0 dates back to (March) 2014; 2.2.x probably from 2016.

I was very careful in updating mine... there are always reports in their forum of things going wrong.   I typically waited a few months, until things settled down (like when Joe53 reviewed the product here and gave it a "thumbs up").  But eventually, I did update, and don't believe I encountered any problems.

I am satisfied with 4.1.x ; I have installed 4.2 on one system, but not had any time to test it out.

In theory, a "lifetime" license should be honored.  It should be automatically acknowledged during the update, without you having to take any special action.  However, before updating, I would be sure to copy any ID, license #, key, or whatever information you have.   That way, if something goes wrong, you may be able to manually (re-)enter the information if needed.

But I can't make you any promise.  Especially since you'll be "jumping" over version 3.x in the process of going from 2 to 4.   If you decide to proceed, you will have to accept the risk.

I do believe, that if something happens to the license, you'll be able to get help in the MBAM forum to get it reinstated.   If you saved proof of purchase of the lifetime deal, that certainly would help.

The bigger concern is that the user interface (and settings) has changed so much, it may take you a while to get used to everything.

Thanks for the info. It automatically updates and I run scans a couple times a month and it doesn't find any problems, so might just keep it as is. However, I'll check in on the MBAM forum to inquire about the lifetime license issue.