Can't enter break mode at this time

问题

This has been happening increasingly, when I have a sheets.add or sheets.delete in excel VBA. After searching and searching I finally found the official Microsoft support page on it. My question is, does anyone know why I could have stepped through this code just fine over and over, and then all of a sudden it starts doing what Microsoft says it would always do, and is there a way to fix it?

Sub foo()

    Sheets.add
    debug.print "sheet added" 'breakpoint here

End sub

It's as simple as that. You won't be able to recreate it, because the issue I'm asking about is the fact that it doesn't happen at first. It works just fine over and over then randomly presents the error described in the linked Microsoft support page.

回答1:

Here are a few suggestions which are not fool-proof,

Firstly, verify that the error does not occur if a breakpoint is not set.

If it doesn't, try a few other things:

From the VBE Debug menu, "Compile VBA Project", it's worth a shot.
Delete the line entirely. Run the code. Then put the line back in and try again with the breakpoint.
Add a DoEvents statement after the Sheets.Add
Use a MsgBox instead of a breakpoint on a Debug.Print. With the message box displayed, attempt to manually break using ctrl+fn+End. (At this point, "breaking" isn't necessary but it would be interesting to see whether you can break this way)
Put a breakpoint on Sheets.Add instead; practically speaking, there's no reason to put the breakpoint on a Print statement if you can just put it on the preceding line.
Are there any Addins? If so, disable all of them and re-enable one at a time, testing to see which one may contribute to the error.

回答2:

Yet another Excel/VBA glitch.

When it happens to me when I click a button running a macro:

I first try to directly run the macro from VBE,
if it fails, then I put a breakpoint at the first instruction of the macro,
if it still fails, I try both,
or, after clicking the button and breaking on the first breakpoint, I do a single step (SHIFT F8) and then I can let debug run freely as usual (F5).

And so far I don't get this error anymore.

Probably not foolproof either but worth a try.

回答3:

Check if Microsoft for Visual Basic for Applications Extensibility is being referenced/used in the project. This prevents the program having its execution suspended:

Excel helps says specifically:

A change was made programmatically to the project using the extensibility (add-in) object model. This prevents the program from having execution suspended. You can continue running, or end execution, but can't suspend execution.

You are unable to step through code when making changes to the project (dynamically eg using InsertLine etc). the code can be run but not stepped through.

回答4:

Deleting certain objects including ActiveX objects actually changes the VB project. It took me some time to realize that the following line of code prevented the VBE from entering break mode:

Excel.ActiveSheet.DrawingObjects.Delete

If you can identify the code causing the issue, and the order of operations isn't important, move it to the end of your script.

来源：https://stackoverflow.com/questions/33698257/cant-enter-break-mode-at-this-time

标签

excel

vba

debugging

breakpoints

worksheet