Task dates dont update when i move the predecessing task's date.

You may have a circular reference in there somewhere, and they can be notoriously difficult to track down. MSP will stop calculating if you have that.

Nope this is not the case here. It was on.. anything else?

YidesDeutsch --

You might have accidentally hit a keyboard shortcut that disables automatic recalculation of your schedule. Try this:

1. Click File > Options.
2. In the Project Options dialog, click the Schedule tab.
3. Scroll down to the bottom of the dialog.

In the Calculation section, is the On option selected? If not, select it and then click the OK button.

Please let us know if this helps.

YidesDeutsch --

Apply the Gantt Chart view. Right-click on the Duration column header and select the Insert Column item on the shortcut menu. In the list of available columns, select the Constraint Type column. In the Constraint Type column header, click the arrow button (the AutoFilter button) and examine the constraints used in this project. Do you see a FNLT, MSO, or MFO constraint on the list? That would reveal why the schedule is not moving. Let us know and we will try to help you.

YidesDeutsch --

What happens if you press the F9 function key on your computer keyboard? Pressing that key forces a manual recalculation of the project. Does that work?

If not, do you have any downstream tasks that include a Finish No Later Than constraint, or either a Must Start On or Must Finish On constraint? If so, those constraints could prevent the schedule from moving. Let us know and we will try to help you.