X299 motherboard doesn't fit DDR4 memory?!

[hobib_ali]

I have a gigabyte X299 Aorus Ultra Gaming Pro motherboard

I spent six hours building my new build

On the part where i install Corsair DDR4 Vengeance RGB Pro 3000mhz sticks. 8gb per stick

But as i place the stick in the motherboard memory slot it doesn't fit in?

Is this RAM not compatible with my mobo, i thought all DDR4 modules fit on x299 board's

I don't want to apply to much pressure in fear of breaking my hardware

Please advise, standing by

 

[hobib_ali]

Ok so the slots are very stiff, so stiff that inserted the ram modules made a grinding noise, carefully inserted trying not to bend/break pins contacts in ram slots, ...

Anyway 1st time boot successful straight into Windows installation screen, 70%done