Browning of leaf tips usually means your Masdevallia needs more humidity, if your growing in your home set your plant on a gravel filled saucer filled with water (Humidity Tray) to add more humidity to the surrounding air, or if you have a humidifier move it closer to your plants. Chlorinated water (Tap) and over fertilising can also cause browning of the tips.You could try running clear clean water through the potting media (Flushing) until it runs clear out of the drainage holes, then hold off fertilising for a couple of months. Any damaged leaves can be trimmed off.