boot - New kind of "The system is running in low-graphics mode" error? Ubuntu 16.04

Hello everybody my first post here.

Specs: Intel Core i5-6200U 4GB RAM 128GB SSD

Ubuntu 16.04 user here.

So before my laptop messed up when I edited the /etc/lightdm/lightdm.conf file in reference to this thread as I wanted to remove the Ubuntu guest session. I added this text to the file allow-guest=falseand saved.

Since the next restart I am now stuck with the error "The system is running in low-graphics mode". However, looking through forums I have not been able to find a solution suggested by others in the comments.

When trying to load the recovery menu (by holding shift) it does nothing and carry's on and boots into the error. Once in the error I cannot carry out any of the options such as "Edit configuration file" as it just doesn't open.

Other solutions were to get into a command line using CTRL + ALT + F1 which also does not work (does nothing) and exiting to the console login just gives me this.

And does nothing after. Others are saying that this issue could be disk size related however, I had around 100GB+ storage space available.

I thought maybe I could boot into BIOS and re-install Ubuntu however, I cannot seem to get access to it. Have tried booting and using keys F10 F5 Delete F1 and F2.

For more context I have made a short video recording the problems I am having.

Hope someone can help me.

EDIT: /etc/modprobe.d/local.conf

options drm_kms_helper poll=N

/etc/lightdm/lightdm.conf

allow-guest=false

EDIT 2:

From the comments...

Problem #1:

Adding "allow-guest=false" to /etc/lightdm/lightdm.conf resulted in an incomplete lightdm.conf file. The correct file should look like this:

[LightDM]
[SeatDefaults]
allow-guest=false

Problem #2:

An invalid or incompatible options statement for the video driver was added to /etc/modprobe.d/local.conf. Removing "options drm_kms_helper poll=N" solved it.