What does “An internal application error has occurred” mean?

It’s hard to pinpoint the cause of the error without more detailed information. The problem with this error message is that it doesn’t say much beyond the fact that the software is unable to process certain information that has been transmitted to it. 

This could be due to any one of countless reasons; usually, there is either an error with the survey structure (e.g. an incorrect link if the survey is launched from an external source) or another problem on the respondent’s side (browser add-ons that interfere with the transfer of links, malware). 

If multiple respondents are affected by the error, please get in contact with Tivian support.