KB5002121 breaks MS Access runtime applications

We could see this on customers running our app with Access 2016, 2013 and also those using Access out of Microsoft 365 (here Version 2206 brings in this behaviour).
Dramatically as we talk about more than 1000 computers in Europe and Asia!

If you set Options , aktive database, open form on startup to "no form" (all translated, english might be different in Office) It works.
However in most cases the startform will call procedures for connection, login... so not posisble to do.

We found a dependency to form complexity. A simple form in open event only a message box works. But if in open a call for functions in modules exists, the error comes up.
Latest workarround: simple form in options, on simple form a button to call the original start form. Test in the smaller app with Microsoft 365 Access was acceptable. simple form opend and on click opened the real form. However we noticed if you click immediately after form is visible you get the error and have to click twice.

Thanks for posting that solution. However, as I recall the last time there was a major bug was a few months ago and it was fixed within a couple of days transparently to the users. There was an issue last year, that did take several weeks to produce a fix.

If anyone is looking for a solution for the time being, I found something that works for me.

If I create a blank form with no codebehind, and add an extra step at the beginning of the AutoExec macro to open that form first, and then open the real form afterward, it does not throw any errors. I can then add another step in the macro to close that blank form and continue on my way.

(last time microsoft broke access with a security update like this it took them over a month to fix it, so I started looking for ways to deal with it)

With regards to the July Microsoft patch Tuesday updates rolled out yesterday it's not just update KB5002121 (Security Update to Microsoft Office 2013), it is also caused by KB5002112 (Security Update to Microsoft Office 2016).

The issue applies to compiled databases (e.g. MDEs etc.), not uncompiled (MDBs) that I have seen, and is not limited to the runtime versions of Access as I first thought unfortunately.

You do not need to uninstall Access (unless one of the many other updates not mentioned here break your databases as well), just uninstall the relevant VBE7.dll file update, as above.

FYI there were other updates that updated some of our other dependencies such as MSO.dll, ieframe.dll etc, so it depends what other references you are using but it was only the VBE7,dll update that fixed our database issues.
https://www.reddit.com/r/MSAccess/comments/vy5wtr/issues_with_kb5002112kb5002121_vbe7dll/(this was my original post on this)

Just as an addendum - not sure, whether the team is aware (hadn't reported yet, but several of my blog reader). A summary may be found at.

Office updates destroys Access run time and apps

There are also a couple of comments from affected users within the cross linked German blog post. It affects Office 2013, 2016 (MSI) and also Office 65 (C2R).