Drawing isn't letting me select objects

[IlliniEI]

I've come across this issue multiple times in several drawing files and just wanted to see if I'm the only one. I will be working in a drawing and suddenly it will stop letting me select objects. For example, I go to select a polyline and it returns "ERROR: Invalid Selection Set!". On the screen I can see the objects highlighted as if they were selected, but my properties bar shows that there is no selection, and I cannot manipulate the objects at all. The only fix I have found is to save the drawing and restart the program. Has anyone else run into this and found a solution? I'm running 2021.

[rl_jackson]

I have had this come up, and the only solution is to save and close.... C3D just flakes out for a bit.

Another cause of this is having more than one drawing file open at a time, sometimes it gets lost as to which drawing is active. Again the best solution is to save, close and restart C3D (oh, and don't have multiple files open)

[IlliniEI]

One thing I've noticed is that, if I have multiple drawings open and it happens, closing one of the drawings fixes it. It's strange. For example, this morning I had 5 drawings open, and it happened. I closed just one of the drawings without restarting Civil 3D, and it fixed the problem (until it happened again anyways.) It seems to be tied to having multiple drawings open like you said. Thanks for the reply!

[AllenJessup]

I've had the same issue. Much the same as @rl_jackson . If you have multiple files open. Try switching to another tab and back to the one you were in. That might refocus the program.

[ecfernandez]

It was the same for me. When that happens, I close C3D and open my drawing again as well. It would be good to have a solution provided directly by Autodesk.

[Anonymous]

Any resolutions with this issue besides closing the software down and restarting? Experiencing this with only 1 drawing open.

[klugb]

I have had similar issues and type "plan" and set to world.

Works for me.