This is commonly known as an “indexed-repeat error.” It occurs when a field that is inside a repeat group is directly referenced from outside that repeat group.
This error means that somewhere in your form definition you have referred to a field that does not actually exist as a field in your form.
You have received this error because the total number of begin group/begin repeat rows in your form does not match the total number of end group/end repeat rows.
You have a calculate, relevance, or constraint expression that has a syntax error that makes the expression incorrect.
This error appears when your Collect Android app tries to communicate with your server but can't establish a secure (SSL/HTTPS) connection.
This error message means that the Collect app has encountered an issue that prevents it from functioning.
You have received an error in your ODK form that says only questions are allowed in the field-list.
A dependency cycle error typically indicates that through a series of relevance interdependencies, a field in your form is now relevant upon its own value, which is logically impossible.
This error means that whichever ODK-based Collect Android app you are using can’t connect to your ODK or ODK-based platform’s server.
We should hope for a post-ICT4D world that promotes an ecosystem of technology providers instead of hindering them.