Very often your career is stuck because:
1. Your bosses are very happy with your performance on your current place and don't see any reason to change anything ("on this position you are the best and it's the way to go");
2. There is a high level of job security and good benefits (usually in public sector) that keeps you frozen on your chair;
3. Also, there is a high level of job insecurity and much less benefits elsewhere ("Baby, it's cold outside");
5. There are not so much opportunities to work with newer technologies, because your management decided so;
6. You are reluctant to have a serious talk with your superiors because of some fear to jeopardize your current status.