No search fields in Cashiering Receipt Entry

After selecting the Payment type on Cashiering Receipt Entry page, all search fields are missing. 

System Administration > External systems perpetually loads. 

• Cashiering
• 2021.1+
• Receipt Entry
• Payment Types
• External Systems

Application pool is hung

Recycle Application pool

On-Premise clients

•  How to Recycle an Application Pool in IIS
• Contact support if additional assistance is needed

Hosted/SaaS clients

• Create a case with TSM SaaS for further assistance via the Support portal

Users should be warned before recycling application pools.

Search fields missing may be paired with the error, Sorry there was a problem loading the external system payment type for external payment type. 

• Cashiering Sorry there was a problem loading the external system payment type for external payment type