Every time I go to select a premade character my game crashes. Win 10 64bit. Any ideas? Happens with and without mods installed.

I seem to remember something like this happening, after I played a module that had a custom character class override. After I was done the module I removed the override, but not the character, so that character caused an issue even trying to look at it.

If it is an issue like that:
Go to your location for characters, and sort by date, and temporarily move all but the oldest ones into another directory and try again. If it doesn't crash, you can start moving them back until you find the problem character.

A more complete option is to rename the characters folder entirely (e.g., to something like "oldcharacters"). Restart NWN 2, and the folder should be recreated with its original contents. Now try loading one of those characters and see if the crash occurs.

Also, if you're using mods, be certain you are installing them into the NWN 2 directory in your Documents folder, not into the main game folder.

Note that some mods require you to install files (such as .tlk files) into the NWN 2 root folder in your Documents directory (vice the tlk subdirectory). If you want to be certain that you're starting from a clean location, rename the NWN 2 folder in your Documents directory and restart the game. This should recreate the entire directory for you.