The 'time limit exceeded' (TLE) error arises when your solution's time complexity is too high, making it unable to process inputs within the allowed time. To fix TLE issues, start by analyzing your code's time complexity and try reducing nested loops or repetitive calculations. Data structures like hash maps, sets, or priority queues often provide faster lookups, which can speed up solutions significantly. If you're using recursive approaches, consider converting them to iterative or dynamic programming solutions to avoid stack overflow and optimize calculations. In cases where you have large constraints, moving from O(n^2) to O(n log n) or O(n) can make a huge difference. Reviewing common algorithms, such as binary search or fast sorting methods, can also help in optimizing your solution for TLE issues.