How do you deal with "stoppers"?

Question

Work organization

Sometimes it happens that some task takes more time than it has and you continue to work on it to the detriment of other tasks and goals in order to achieve some kind of finished result, and as a result, this can lead to the fact that time passes, but there is no result - those. you are in "stop". As a result, this can lead to the fact that many tasks begin to hang.
How do you deal with such situations?

Answer 1

1) Take on another task. Then return to this one.
2) Think, maybe you can do without this problematic one.
3) Go in a radically different way, perhaps from scratch.
4) Discuss with the customer / manager the issue of removing / simplifying the task

Answer 2

All answers here will be useless.
Learn to prioritize and calculate your strengths.

Answer 3

If the task is not solved, then most likely it is not relevant.
When a tooth hurts badly, then you run to the dentist, and do not hesitate.