Just updated to the latest version. It looks like escort/formation orders still aren’t working so well. This is a screen shot of what happens when I set target (click for full size - forum cuts the right off a bit):
Notice that the deployment area now reflects the relationship between my cruiser and the frigates that are supposed to be flying in formation with it. The Formation'' order dialog, however, does not reflect the target, thus the OK’’ button is disabled. I have no choice but to delete the order.
Further testing shows that if I place a set of ships in the deployment area and set their formation target, it works. If I break that formation by dragging the cruiser out (deleting it), none of its attached ships can have a new Formation order issued. I have to delete all the little frigates and re-add them to the deployment area -OR- add a single new frigate to the group I am giving the order to.
Hrm. It worked like this when I was doing my test a few minutes ago. I just put a completely new cruiser + all new frigate group to fly in formation with it (19 ships) and had the set target bug happen.
I’ll fool around with it a bit more and see if I can get some reliable reproduction steps.
I’m mostly sure the issue you’re seeing has to do with group selections with the mouse, rather than with the previous target being deleted. Clicking on any of the ships in the group should let you assign the order.
On a related note, I hit a CTD when the target of a formation order got removed from my deployment. I was very close to my budget limit when I edited one of my cruiser designs, making it more expensive, and so making the deployment over budget. At first it seemed to have done a more or less reasonable thing by removin all of the cruisers of the class I had just edited. The crash came when I noticed that the formation order still showed up on one of the ships that had been targeting one of the removed cruisers. Clicking on the order caused the crash.