[Solved] Installing 16.04 or Upgrading from 14.04 Crashes to Blinking Cursor

[theimmortal]

I'm really sorry for what will probably be a quick fix, and I don't know what information to provide to help diagnose the issue here. I've spent the last two days' free time trying to properly re-install the most standard version of Ubuntu on VirtualBox.

This initially started because I accepted an update for VBox to the most recent edition (5.2.8 r121009). Suddenly I was unable to startup any of my local Ubuntu VBoxes.

Thought process:
- This must be a problem with my VBox update. I attempted to downgrade VBox to a prior version. No luck. I went back at 5.2.8.

- This must be a problem with the boot operation. I downloaded the most recent ISOs from Ubuntu 16.04 to recover it.
+ Using the original/problematic VBox, the ISO disc would not load - it went straight to the flashing cursor.
+ If booted to HD, GRUB menu would appear. Any boot options would return to flashing cursor. No luck.

- This is taking too much time - make a new one. I attempted to create a brand-new VBox with my fresh ISO on my fresh install of VBox.
+ In the new VBox, the ISO would load directly to the blank screen with blinking cursor.

- Maybe there is a problem with Ubuntu's ISO. I downloaded it from another source. No change.

- There might be some incongruity with 16.04 and the newest version of VBox. I downloaded 14.04's ISO. PROGRESS! This worked, and I was able to install through Guest Additions, but once I tried to update it the system crashed and has returned to that cursor.

Log files are attached here:

Logs.zip

(39.54 KiB) Downloaded 14 times

[socratis]

Log file on the new VBox is too big.

Even if you ZIP it? Which BTW you should do for your existing "Initially Broken VBox.txt" log; edit your message and replace the log with its ZIPPED version. It helps save a (virtual) tree or two...

00:00:01.952791 HM: HMR3Init: Falling back to raw-mode: VT-x is disabled in the BIOS for all CPU modes

You need to address this. Your i7-7500U certainly supports it.

[theimmortal]

Even if you ZIP it? Which BTW you should do for your existing "Initially Broken VBox.txt" log; edit your message and replace the log with its ZIPPED version. It helps save a (virtual) tree or two...

You, sir, are smarter than me. Thank you. I've attached both here and deleted the original.

00:00:01.952791 HM: HMR3Init: Falling back to raw-mode: VT-x is disabled in the BIOS for all CPU modes

I will look into a fix for that. It runs pretty slow!

[theimmortal]

I fixed the VT-X settings on my Windows PC by changing the settings for UEFI and rebooting to BIOS. Now I can use multiple cores of memory for VBox, and I can enable settings like PAE/NX (System>Processor) and VT-X (System>Acceleration). The added memory set up the system to actually follow through with the boot. I was able to download a boot-repair ISO and, after running it two times, was successful in repairing GRUB.

Just in case anybody reads the same threads I did previously: do not change your network host settings. I read some strange forum results and changed my host name, which started to spam my email with rootkit warnings. But that's easy to fix.

[socratis]

Glad you got it going. Marking as [Solved].