A user may encounter the following error during a terraform run on TFE:
Error fetching plan data
Cannot read properties of null (reading 'length')
This is a known issue affecting TFE releases prior to 202210-1 . It is triggered when JSON-encoded arrays are compared with null values.
Overview of possible solutions
1. Switch the Workspace's User Interface Setting from Structured Run Output to Console UI.
2. Upgrade to Terraform Enterprise 202210-1 (659) or later.
After applying one of the solutions, retry the failed run and it should not run into this error.