Mac testing result

It's a memory error. Make sure your RAM is properly seated in the slots. If it is then first remove one RAM module then the other, testing after each. It's a process of elimination to find the bad module.

You can not continue to use a Mac with bad RAM memory for anything you care about. At any moment, it can execute a bad instruction and go wandering off, or trashing the data on your hard drive, or worse.

The Mac does not know how to 'sequester' bad RAM. it MUST be repaired by replacement.

If you bought third-party RAM that has a Vendor sticker on it (not just a manufacturer sticker) it may have a lifetime warranty. Call the Vendor and ask them to replace BOTH modules. (They have a machine that can isolate which was the problem module later.)