LAMBDA function not supported anymore?

Brass Contributor



I am signed up for the Office Insider Current Channel (Preview) and currently have version 2111 build 16.0.14701.20240 installed.


As soon as the LAMBDA function was released for Office Insiders, I created several Workbooks using LAMBDA functions in them. They all worked like a charm. However, after a few days of not using those Workbooks, I opened one of them and found a #NAME? error (unsupported function) in every single cell where the LAMBDA function was being used.

When I opened Name Manager, I found something like this (it's from one of the function's online examples):

=_xlfn.LAMBDA(_xlpm.a,_xlpm.b,SQRT((_xlpm.a^2 + _xlpm.b^2))).


The other Workbooks are showing the same issue. I closed the Workbooks without saving.


Was the LAMBDA function deprecated? I checked my account and I am still on the Current Channel (Preview) with no pending updates.

21 Replies
LAMBDA is only available for Office insiders, have you switched channel or turned off insiders by any chance?
Hello Jan, I haven't switched the channel. I actually checked my account in Excel and I am still on the Current Channel (Preview).

@Carlos Spörk 

I'm on


(E3 subscription) and LAMBDA() is available



@SergeiBaklan Interesting, mine reads:


(also E3)

@Jan Karel Pieterse 

I have both Beta and Current (Preview). Don't know why, but now on the latest I have practically the same functionality as on Beta, in particular

- LAMBDA() itself

- lambdas helper functions as MAP(), REDUCE(), etc

- PowerPlatform.DataFlows() in PQ

@Carlos Spörk New features of Excel are "flighted", which means only part of all users in a certain channel get them. It sounds as if something went wrong during an update of Office and you lost access to this feature. You can try fully removing Office and re-installing it, hoping you get the feature back. But it is a lottery unfortunately.

Check out this article about the different channels of Office:

Well, that behavior of functions availability on a random criteria is definitely rude. We're after all supposed to test and provide feedback on preview or beta features. And now I find out that some of the workbooks I created are probably not going to be of any use whatsoever until the LAMBDA function is released to the general public?
Btw, completely uninstalling and reinstalling Microsoft 365 only to see if I'm lucky to win the lottery would be a waste of time.

According to what I heard, all Insiders should have access to LAMBDA now. Try Launching Excel, then killing its process using Taks manager, then launching it again. If that fails, I suggest to let it update itself. If no updates are available, I think your last straw is an on-line repair of Office.

@Jan Karel Pieterse Yesterday I uninstalled and reinstalled Office (after rebooting). After reinstalling, I made sure I was still subscribed to the Office Insider's Current Channel (Preview), and I already had an update available for the Current Channel. Still, the LAMBDA function is not available. I will wait for the next update. Based on what you've heard, I might get the function back with that update. Thank you so much for your help!


Funny thing is, the function works just fine when I open any of the workbooks using the LAMBDA function in Excel for Android.

@Carlos Spörk I got official response about this, which comes down to:


we’ve sometimes seen people lose flighted features when they should still have those flights, some reasons are,

  • they switched their channel
  • they switched their account
  • they upgraded / downgraded their build, or performed a clean install
  • (some less common scenarios)

I know that doesn't solve your issue though.

best response confirmed by Carlos Spörk (Brass Contributor)

@Carlos Spörk Do you have multiple 365 accounts by any chance? If so, try signing out of all but one and then let Office update itself.

@Jan Karel Pieterse None of the three first scenarios in the official response apply in my case. True, I performed a clean install, but that was after posting my problem. 

@Jan Karel Pieterse Yes, I have another Microsoft 365 account for Visio on my laptop (a work/school account), but I signed out of that account and uninstalled Visio before reinstalling Microsoft 365 Home. There are two other Windows accounts on my laptop, but I'm not sharing my Microsoft 365 Home subscription with them, and I know for a fact that they've never used Office on this laptop. Anyway, when I open the account settings in Excel, I am the only one signed in, and the "belongs to" section matches my MS 365 Home subscription's email. For the time being, I will wait to see what happens when I get a new update for the Current Channel and will post an update here.


@Jan Karel Pieterse Well, after waiting for almost 3 weeks I've got the latest update for the Current Channel (Preview) and lo and behold, the LAMBDA function is back, and all of my workbooks are working again. Before that, I had already followed your suggestion to sign out of my other 365 accounts.

Thank you so much for your help!

@Jan Karel Pieterse @Carlos Spörk


Just to say this is (probably) what happened to me; my son took me through a move from gmail to Outlook, which involved setting up a different (personalized) email address, to which I had to transfer my Office365 subscription. I then found - quite by chance - that the lambda functionality had disappeared.


I immediately:

* subscribed (with the new email account) to the office insider programme

* did an online repair of office

... but have not yet got lambdas working


I am hoping that they "come back" with a future update.


Curiously (to my simple mind) MS first line tech support gave up and wouldn't refer me further to technicians, instead giving me a number of community links (which led to this). My hopes rather fell when the person taking over my machine seemed really confused about my customized ribbon  :)


Best wishes

Andrew Howe


I am almost certain that, at least in my case, the multiple Office 365 accounts were the root cause for the missing LAMBDA function.


As for your comment regarding the tech rep's confusion with your customized ribbon: Before starting a support chat or call, I always make sure to take a screenshot and then reset every custom layout on my Office apps. It usually saves us both a lot of time...  ;)

@Andrew_Howe Try going into File, Account and click the Update options, Check for updates button.
1 best response

Accepted Solutions
best response confirmed by Carlos Spörk (Brass Contributor)

@Carlos Spörk Do you have multiple 365 accounts by any chance? If so, try signing out of all but one and then let Office update itself.

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