Fatal error installing development snapshot (fixed)

[abbleeker]

When Windows 11 started to enforce the TPM 2.0 requirement, I tried to install it in a virtual machine using Virtualbox, like I had done earlier with Windows 10. I soon found out that the current version, Virtualbox 6.1.28, had no support for a TPM. But after looking on the Net for more information, I found posts claiming that the developers were working on adding a TPM, and that VB 7.0 would support it. I then discovered the VB test builds page, and I noticed that there were two kinds available, the test builds of 6.1.29, and the development snapshots of 6.1.97. The test builds don't support a TPM, but the development snapshot were supposed to offer some kind of support, because they're actually builds of VB 7.0. Unfortunately, I was unable to install these builds, as the installation program aborted immediately with a fatal error. I found some posts that said that this was an MSI issue, not a VB issue. They offered some tips to resolve the issue, but none of them worked. But at least some of them showed me how to create a log file. The log file told me the installation program had tried to find Python, and had failed. That was odd in a way, because Python 3 already was installed, but obviously wasn't detected. Later I realised that this was happening because I had been working on a project that needed the 32 bits version, so that was the one I had installed. I then decided to install the 64 bits version to see if that was causing the problem, and it actually was! After that the installation program ran without any problems.

I was happy that I had found a fix, but it seems a bit weird. Do you really need to have Python 3 installed to install VB 6.1.97? I would think there should be quite a number of people who'd like to try VB 7, who don't have Python installed. I haven't been able to find posts urging you to install Python first anyway. And if you have to, shouldn't VB tell you so? But maybe that's just this machine? Have other people been able to install VB 6.1.97 without having Python installed?

[scottgus1]

I just installed 6.1.97 on my test Windows 10 host. The installer had a warning (which I had to read a few times to be sure I got it) which seems to say that if the Python API is wanted, Python 3 nerds to be preinstalled. My 10 host does not have Python 3. I let the installer continue, it finished successfully, and VMs run.

I don't think Virtualbox on Windows hosts requires Python 3. Could be that since you already had it installed, though, Virtualbox tried to interface with it and failed.

[abbleeker]

Thanks for the confirmation! I was expecting that actually, it seemed weird for VB 6.1.97, and possibly VB 7.0 when it's released, to expect that 64bit Python would be installed. I suspect that something in the configuration of this box confuses the VB install script. It somehow seems to conclude that 64 bits Python is available, and then can't find it. This is probably why it aborts installation with a fatal error. Installing 64 bits Python obviously satisfies its checks, and it will then happily install VB with no issues after that. Unfortunately I have no idea what exactly causes the confusion, so I can't fix it, but at least I can now install install the current development build.