You cannot.
It is the only contraint you can never override : project with real work cannot be deleted.

Thanks Babynus.

It should be a good idea to make this function (delete or disable from task view) and able from only Admin user .

I will study the request, but could be very (very) dangerous because you will have to delete the existing work for this project.
And then you could deleted real work from valaidated weeks.
All figures could become wrong.

I'll study the subject, but really is is very (dud I already sayd very) dangerous.

Yes you are right, it is very dangerous 👿 ... but perhaps useful in some case. B)

I can suggest long way for it, but it works.

For activities user must delete his hours.
Then you must delete affectation hours for work.
After it activity has zero hours in assigned and real work.
After it you can delete work.

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Other way (very very dangerous).
You can directly delete rows in database.
But you can corrupt database and links between tables.

Thanks for yours suggestions, a way exists!!!

but I think it is too manual...that's why I proposed to Babynus to develop an automatic solution into ProjeQtOr.

Yes, it's very manual.
But I agree with Babynus that you request is very dangerous and for me very strange.
Better keep accuracy and order!
And create additional platform for tests.

You are right, but I have no test platform ;-(