Signals Notebook: "Failed to communicate with PubChem" error when attempting to update reagent information

When users try to update reagent data from PubChem in Signals Notebook, they may encounter a "Failed to communicate with PubChem" error message. This error can occur even when PubChem services are functioning normally and the CAS number being searched is valid.

Root Cause: The issue is typically caused by incorrect PubChem Mapping configuration where essential data fields are not enabled for synchronization.

The following error is found within the browser network log:

Error Response:

Status: 400 Bad Request
Error Message: "No valid mapped data available."
Error ID: errid:70d5be4b

• Solution: 
  1. Navigate to the PubChem Mapping settings in Signals Notebook
  2. Verify that the required fields are checked/enabled:
• Chemical Name.
• Synonyms.
• Density.
• GHS Signal Word.
• Hazard Statements.
• Precautionary Statements.
• GHS Hazards.

3. Save the configuration changes
4. Retry updating the reagent information from PubChem

**Additional Notes:** This configuration issue may affect multiple CAS numbers and reagents. Once the mapping fields are properly enabled, users should be able to successfully update reagent data from PubChem without encountering the communication error.