Lost Joins and Invalid Fields When Editing the Data Source Connection to Point to a New Server

Issue

When editing the data source connection to point to a new server that is supposedly the exact same in content (Schema, Tables, Column names) some joins are lost and fields are invalidated.

Additionally, the following error might occur:

TableauException: Field [field name] which is included in a join clause, does not exist.

Environment

Tableau Desktop
Multiple data sources

Resolution

Ensure that all Column names are exactly the same on both data sources.

Cause

Joins are lost and Fields invalid because the Column names in the Source Tables and Target Tables are not the same, hence Tableau Desktop is not able to establish relationships and replace accordingly.