Memtest86+ crashing
Solution 1:
First, be sure you are running the most current version of MemTest86, which is version 3.5 at the time of this writing.
Put your old RAM back in and run MemTest86 again. If MemTest86 crashes in the same way, then you know that the problem is not with the new RAM. If MemTest86 does not crash, then you have more testing to do.
If you have access to a different laptop that can use the new RAM you purchased, you should install the new RAM into that other laptop and run MemTest86 there. If Memtest86 crashes in the same way on that laptop, then you can be relatively sure that the problem is with the new RAM.
If you are unable to get access to any other hardware that can handle the new RAM, consider returning the new RAM where you got it from and getting some other new modules. If this is infeasible, you probably chose a poor vendor for RAM in the first place.
Also, you could also try using MemTest86+, whose current version is 4.00, which was released within the last six weeks. I believe that MemTest86+ is based on the original MemTest86, but is maintained by a different group. I know that I have had similar good experiences with MemTest86+ as well with the original MemTest86.
Solution 2:
Interesting problem.
It could be indicative of a hardware problem, but I'm inclined to check your copy of Memtest first.
Does the same copy of memtest run OK on other computers?
Does the same copy of memtest run OK on this computer with the old RAM?
Does a different copy of memtest run OK on this computer with this RAM? ("Another version" of memtest would be best, but "same version, downloaded separately & burned again" works too.)
Start there and then proceed with eleven81's suggestions regarding the hardware.