Memory error when using the file manager

[Jmes]

Whenever I use the new file manager and try to click on a button, the VM crashes and the following error message appears:
"The instruction 0x00000000 referenced memory at 0x00000000. The memory could not be written. Click OK to terminate the program"

I can reproduce this error using the VBox file transfer tools. With the new file manager, it appears every time I hover over an action button of the interface. It seems like it occurs when the mouseover tooltip is supposed to appear.
Sometimes it happens when I use the drag&drop file transfer, but I it less frequent. The file manager makes it 100% reproducable for all VMs.
Virtualbox is the only app that responds to this and it happens only when within the file transfer context of a running VM. The tooltips of the main app work just fine.

Running sfc /scannow in cmd fixed the problem. I'm using a Windows 7 machine and I use Universal Theme Patcher to run a custom theme. It makes changes to themeservice.dll, themeui.dll and uxtheme.dll. Reverting these changes manually fixes the virtualbox crashes, but of course it also breaks my theme.

I've been wondering if there's a way to make both work? Using hotkeys for file transfer would allow me to skip the action buttons, but if I'm not mistaken there are not hotkeys for the file manager.

Thanks.

[Whiskeyjack]

Hi. This sounds like a more generic error rather than a bug in File manager. Do you see a similar crash in other Qt5 applications. To be honest I have very little motivation to patch (and you have provided very little info how to do this) my Windows and test this. I am afraid if the problem persist you will have to use VirtualBox on a non-patched Win7.

[mpack]

Is this while a VM is running, or just the manager? Because it sounds like a typical hardening problem with a VM: some DLL was unsigned and got ditched, some other third party DLL is still making calls (or accessing data from) the discarded DLL. The fix is to get the vendors to sign their DLLs, or stop hacking system DLLs and thereby invalidating the signatures.

[Whiskeyjack]

Is this while a VM is running, or just the manager?

In the current architecture it is not possible to run a file manager instance from a manager UI (unlike for example the machine log viewer). That is it is only plausible to run it from a machine UI.

[Jmes]

I have only experienced these crashes using the VirtualBox file manage rand a running VM . Other Qt5 apps work fine and apart from those file transfer errors VirtualBox itself works just fine as well.

mpack, I think you're right about the signatures. I understand that this isn't a VirtualBox issue so I will just revert the file changes. Thank you.