Describe the bug

If an invalid configuration is imported in the UI, it shows a red error box in the modal for a split second but then ends up showing that it was successfully submitted. This only happens in certain cases. We'll need to narrow down what's causing it.

Edit: Changing the "masque_strings" field in the configuration file and then importing it causes no error at all. Nothing in the modal changes.

To Reproduce

Steps to reproduce the behavior:

1. Export the default configuration
2. Modify it to rename "payloads" to something else
3. Try to import it
4. See the red error box in the import modal for a split second before it goes away
5. See at the bottom that it says the configuration was imported successfully

Expected behavior

Properly show the error if the configuration is invalid

Screenshots