Large text area field causes connection reset (ERR_CONNECTION_RESET) - Support and Troubleshooting

Large text area field causes connection reset (ERR_CONNECTION_RESET) Description  When opening a form that has a large text area field (~1.5MB), and then click the ServiceNow back button (not the one in the browser), the message "This site can't be reached" is displayed.

The browser also displays the error message "The connection was reset" (ERR_CONNECTION_RESET).

Cause Tomcat has the parameter maxPostSize to limit the maximum size in bytes for POST requests that are handled by the container FORM URL parameter parsing. By default, this limit is 2MB, and ServiceNow instances do not override this value.

The ServiceNow text area has a hidden input field that copies everything in the text area, which doubles the POST size, that is why a text field with ~1.5M characters is actually oversized.

The parameter maxPostSize applies only when request contentType is "application/x-www-form-urlencoded", REST/SOAP and attachments will not be affected.

Resolution Use attachments instead of inserting content into large text fields.