CorruptModelException during work item execution

I'm totally new with the Forge design-automation (V3 Beta)

During the work item execution inside the design-automation framework, the CorruptModelException is thrown.

The model (.rvt) being sent will open without problem in the desktop environment (R2018).

I tried to purge unused and resaved, but it didn't help. Here's the part from the log that tells the problem.

[04/17/2019 10:11:16] Found an addIn for registration: xxx.addin
[04/17/2019 10:11:16] Initializing RCE....
[04/17/2019 10:11:16] Initializing RevitCoreEngine (and possibly running stub installer)...
[04/17/2019 10:11:16] Language not specified, using English as default
[04/17/2019 10:11:18] Initialize and  get RCE: (VersionBuild) 18.0.0.0 (VersionNumber) 2018 (SubVersionNumber) 2018.3
[04/17/2019 10:11:18] Autodesk.Revit.Exceptions.CorruptModelException: The model could not be opened: Unspecified error
[04/17/2019 10:11:18]  (COleException 0x80004005)
[04/17/2019 10:11:18]    at Autodesk.Revit.ApplicationServices.Application.OpenDocumentFile(String fileName)
[04/17/2019 10:11:18]    at DesignAutomationFramework.DesignAutomationData..ctor(Application revitApp, String mainModelPath)
[04/17/2019 10:11:18]    at DesignAutomationFramework.DesignAutomationReadyEventArgs..ctor(Application revitApp, String mainModelPath)
[04/17/2019 10:11:18]    at DesignAutomationFramework.DesignAutomationBridge.SetDesignAutomationReady(Application revitApp, String mainModelPath)
[04/17/2019 10:11:18]    at RevitCoreEngineTest.RceConsoleApplication.Program.UserMain(CommandLineArgs cl)
[04/17/2019 10:11:22] RESULT: Failure - Result of running user app is failure
[04/17/2019 10:11:22] Finished running.  Process will return: TestError
[04/17/2019 10:11:22] ====== Revit finished running: revitcoreconsole ======
[04/17/2019 10:11:22] Process exit code: 4
[04/17/2019 10:11:22] End Revit Core Engine standard output dump.
[04/17/2019 10:11:22] Error: Application revitcoreconsole.exe exits with code 4 which indicates an error.
[04/17/2019 10:11:22] End script phase.
[04/17/2019 10:11:22] Error: An unexpected error happened during phase CoreEngineExecution of job.
[04/17/2019 10:11:22] Job finished with result FailedExecution

One example file I'm tryuing to use can be found from here: https://www.dropbox.com/s/chffmh62wlmuwx7/empty.rvt?dl=0

Could someone test, whether he can use this with Revit 2018 design automation.

I'm also a bit confused about Workitem API. The documentation says that I NEED to use 3 legged auth. (which seems to be awfully difficulty as it requires additional signatures in the request (?)...), but the step by step guide shows it with 2-legged, which is otherwise working OK for me too. This is probably not the reason to my difficulties.

Any ideas...?

The link the provided in the comments is not a direct download link. If you click on the link, it takes you to a webpage:

https://www.dropbox.com/s/chffmh62wlmuwx7/empty.rvt?dl=0

The workitem input arguments need a direct download link to be able to process the file correctly. For example, a direct download link to the exact same file is

https://dl.dropboxusercontent.com/s/chffmh62wlmuwx7/empty.rvt