Increase the H/W buffer size in the preferences menu. The bigger the size, the less stress you place on your machine. While this may slightly lower the quality of the audio, it will make the recording process much smoother and a lot less likely for Pro Tools to crash.
Install another RAM chip in your computer. This allows your machine to process information at a much faster rate, which makes any installed software run smoother. A faster interface is far less prone to crashing and error messages.
Use a second hard drive for your audio samples. By running the interface off one hard drive and storing your samples on the other, you free up a lot of CPU power that can be devoted to keeping the program running smoothly.
Update your plugins by renewing the licenses online. If the licensing or drivers aren't up to date with the version of Pro Tools you are currently using, it will cause a large amount CPU lag and potentially crash the system.
Divert attention to the Pro Tools interface in your CPU power allocations. The more CPU power that the program has to draw from, the smoother it will run and the less likely it will be to crash.