Many exceptions are not indicative of anything being wrong, so can be ignored and debugging safely continued.
This is because the DK uses both the system and its own exceptions to track situations that are not necessarily abnormal. For example, to check if a provided string is a float number, the DK tries to convert the string to a float, which can raise exception.
If you dislike this, a specific exception class can be turned off in the Tool/Debugger Options dialog box.