This has been observed to be a symptom of an intermittent failure to receive a response in the requesting browser from a web service on the Blackbaud NetCommunity Web Server, and a failure by the Blackbaud NetCommunity Web Server to respond to a Form builder postback for unknown reasons.
If Blackbaud hosts your NetCommunity web server:
Click Chat with Support and reference this article
If Blackbaud NetCommunity does not host your NetCommunity web server:Please contact the appropriate software vendor or IT professional for assistance with this process or issue, which is beyond Blackbaud's scope of support.
Alternate temporary solutions:
1. Refresh the Form Builder browser window
1. Close and then re-open the Form Builder browser window