First, I have "rebuilt" Spotlight several times to no avail. That is not the solution here.
MacBook Pro has allocated 370 GB to "system," robbing me of all the hundreds of GBs of hard disk and SS space I should have available. Mine is a mid-2014 15-inch MBP with 2.5 GHz Intel Core i7, 16 GB 1600 MHz DDR3 RAM, 250 GB HDD (?) hard-disk space and 250 GB of solid state space, running MacOS Mojave 10.14.6.
I am constantly getting notifications on my screen that I'm about to run out of space. And I've received several to the effect of "no, you can't do that because you have no space remaining." So it's not a case of just ignoring the constant notifications. The misallocation of space is severely limiting me from using my computer.
BTW, my MBP no longer recognizes my hard disk space. It tells me that I have 500 GB of SSD. What the heck? Could this be the source of the missing space on my computer?
Lost in MacBook Pro land