If you perform an operation that would display a green success message, but instead of waiting for that message you immediately launch another modal dialog, the modal will be cancelled when the table is refreshed and the message is displayed.
Steps to reproduce:
1. Go to Admin > Flavors and Edit a flavor.
2. Press Save (you don't even have to make any changes first)
3. After 'Working...' spinner disappears and the table is drawn and before the success message is displayed, immediately Edit another flavor (or even the some one, it doesn't matter).
4. The 'Loading...' spinner appears, and you may even get to see the dialog briefly.
5. The screen jumps back to the table (cancelling your dialog) and displays the 'Success' message.
This bug not only spoils UX, but also forces to add `time.sleep` into integration tests to make them pass.
I have not been able to reproduce the behavior described here, but I can get a similar behavior by skipping the wait in #3. In other words:
1. Go to Projects, click on 'Modify Quotas' for some project.
2. After quotas tab in modal form appears, change some quota value, click 'Submit'.
3. After 'Working...' spinner disappears and the table is drawn, BEFORE the success message is shown (you may have to be fast here), click on Modify Users (you can also click on Modify Quotas, but Modify Users is faster because there is no pulldown to wait for)
4. The 'Loading...' spinner appears, but when the Success message occurs (from the quota modification), the opening of the new modal will be aborted.
Is this the same behavior that you are seeing?