Digitize Document Error - Error Waiting For Host Service. Timeout: 30000

How to resolve the Digitize Document Error received when " Error waiting for host service. Timeout: 30000" ?

Issue Description: Digitize Document Error: Error waiting for host service. Timeout: 30000

This could also happen anytime an OCR activity is used.

Troubleshooting Steps:

  1. Check which version of the UiAutomation package is being used. Prior to 21.4, the Vision Host executable would try and verify a signature on a package before loading the package. This check could fail with certain scenarios. In 21.4 this check was disabled.
    • Upgrading the UiAutomation package will only work to fix the issue if all the dependency packages are updated.
    • Alternatively, a manual fix can be applied on the machine where the issue occurs:
      • Go to C:\Users\<user>\.nuget\packages\uipath.vision\<version>\build\UiPath.Vision.Host32.exe.config (to check what version to fix, open the project in Studio and check the Vision dependency
      • In the config file, under the <runtime> section add the following: <generatePublisherEvidence enabled="false"/>
  2. If the above approach does not fix the issue, check the Vision host logs on the Robot machine: %localappdata%\UiPath\Logs\<Vision Host Log>
    • The Vision host log will be named based on the OCR engine that is being used in the activities.
  3. Try seeing if the log message helps to understand the issue. There typically would be an error message in the log.
  4. If there is no log message in the log, then that means that communication is broken. At this point share the following details with UiPath Support:
    • %localappdata%\UiPath\Logs\<vision host>
    • Full stack trace of the error
    • OCR engine being used.