To investigate compose failure, it is necessary to collect Diagnostics Package from Qlik Compose
This article explains how to collect Diagnostics Package from Qlik compose
Environment
Qlik Compose
Qlik Compose for Data Warehouse
Login Qlik Compose Console
Open the problematic project
From the Project menu, select Create Diagnostics Package
Depending on your browser settings, the following file will either be automatically downloaded to your designated download folder, or you will be prompted to download it: