I just build a new rig today, R9 280x and a fresh driver Adrenaline 18.5.2. Now this happens:
C:\Claymore>NsGpuCNMiner.exe -pow7 1 -xpool ssl://us-east.cryptonight-hub.miningpoolhub.com:20596 -xwal account.worker -xpsw x
╔════════════════════════════════════════════════════════════════╗
║ Claymore's CryptoNote AMD GPU Miner v11.3 ║
╚════════════════════════════════════════════════════════════════╝
XMR: 2 pools are specified
Main Monero pool is us-east.cryptonight-hub.miningpoolhub.com:20596
C:\Claymore>
What might be the reason?
I tested your configuration and it run OK, no problems. Since this is a new build one thing to look out for is Windows Defender deleting 'NsGpuCNMiner.exe', as it usually does, unless added to exeptions.
I've seen that happen before but it wouldn't display all this stuff: "Claymore's CryptoNote AMD GPU Miner v11.3, XMR: 2 pools are specified", you would just get a simple 'file not found' error and the DOS window would just blink and disappear.