Salesforce is introducing mandatory security updates. To support this, Intellistack is releasing a new Forms for Salesforce managed package version V4.149 on the following timeline:
May 18 - Intellistack releases the new managed package version to Sandbox environments.
May 25 - The new managed package version is released to Production environments.
June 24 - Salesforce enforces the Connected App security update. All Forms for Salesforce customers must be on the new managed package version and have refreshed their OAuth token by this date.
Additional details are available in Salesforce's announcement in the Salesforce Partner Community.