You might be able to restore the previous version (if you have not saved your config after you restored it).
Go to the Misc tab and click the “DFFS Configuration list” button under the heading “Toggle visibility of the configuration lists in all site contents”. Now you can go to site content and find the config list – it is Titled “SPJS-DynamicFormsForSharePoint”. Identify the correct config by looking at the Title column.
The previous version of the config is stored in the “lastGoodConfig” field. Copy this over to the “blob” field, save and retry your form.
You can turn on version control on the config list to help in a similar situation next time.
Alexander