I have a blueprism process which attaches to a web page and performs various actions. The process has been running smoothly for six months, but I am now getting an initial error of "ERROR: Internal : AMI error occurred in WaitStart Stage 'Wait For Detail' on page 'Update Claim' - External AppMan reader thread exited before response from query"
After this Blueprism is unable to perform any online action. I get a message saying that the "Read Thread Is No Longer Alive"
It appears to be caused by the Accessibility and UI identification methods in the App Modeller.
Issue was caused by Microsoft pushing out an update to Sharepoint. Blueprism are aware of the issue and have put a post up notifying users https://help.blueprism.com/Automation-Design/Application-Integration/Active-Accessibility-Spy-Mode/1280268672/Why-does-Active-Accessibility-crash-Blue-Prism-when-spying-SharePoint.htm
I re-engineered logic to use HTML elements. I found that the focus action performed the same as a global mouse click center.