Played without issue for four months. Now, same PC, new GPU, and I can't log in P99

[Agreed]

I resolved the issue, and here is how:

1. Went into BIOS and changed primary display to PCIE rather than IGPU

2. In BIOS, turned on Multi-Monitor IGPU mode

3. Allocated 512MB of RAM to IGPU, up from default 64MB

I can't understand how any of these things would have helped it but it works now. Unruly machine spirits within my PC, quiet now, perhaps.