You are using a Vicasso AppExchange application, and are noticing errors in the Salesforce user interface/email processing following the expiration of the application's license.

When a managed package license expires, the following behaviors will apply:

• Components such as Fields, Visualforce pages, and Lightning Components will no longer be viewable.
• Automation, such as Workflow or Process Builder, which refers to packaged components, may break and disrupt your normal business processes.

Organizations frequently create local automation that ties into a managed package. For example, automation to send a survey on Case Closure may use the packaged "Survey Sent" field on Case. In this scenario, the expired license would cause the automation to fail, ultimately causing the case closure attempt to fail.

If your license has expired is about to expire and you're not planning to purchase/renew the application, we recommend that any local automation which references the managed package component either be adjusted or deactivated, and the managed package be uninstalled. For additional guidance, please refer to the following knowledge article.