I had the same problem for anti air 3rd gens...

It is a bit bothering because it means i lost a cyan blueprint with no résultat...

From my experience it still works if you use accelerators to finish the research immediately, or if you keep the game open.
If you close the game tho, all your resources and blueprints are gone.

Yeah. Using an accelerator is useful. otherwise do not close the game. Your belongings may be lost. Errors decreased after last update. Problems are rare. problems can be solved in the future. I do not find crime, the game came many features. These problems are very normal. We are at the beginning of the problems. we have a long way to go. Have a nice day ☺