FoxPro and .NET Interop
SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
Gravatar is a globally recognized avatar based on your email address. SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Kathy
  All
  Feb 2, 2018 @ 10:20am

Hello,
I had just started enjoying SignalR messaging sample when I decided to test it on other machines.
They have access to the internet but with more security settings that the IT guys wouldn't like to change.
When I run this code for the Chat sample, I get the "OLE IDispatch exception code 0 from mscorlib: One or more errors occurred..." error.

DO ChatClient
loChat = CREATEOBJECT("ChatClient")
loChat.Start()

Still not sure if it's because of the security settings but if so, what would be the minimum setting?
I appreciate any idea on this.
Kathy

Gravatar is a globally recognized avatar based on your email address. re: SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Rick Strahl
  Kathy
  Feb 2, 2018 @ 11:23pm

You need to be able to get an Internet Connection from the application.Specifically if it's Win10 machines you need to be able to make a WebSocket connection. If the machine is locked down there may be no outbound IP traffic allowed at all or no WebSocket connections (which are two way). This could also be an AV/Firewall issue, not necssary a policy in Windows.

If the user is not an admin they the failure will be silent. If the user is non-logged in Admin Windows should show a dialog that asks whether ports should be opened and firewall rules added.

+++ Rick ---

Gravatar is a globally recognized avatar based on your email address. re: SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Kathy
  Rick Strahl
  Feb 12, 2018 @ 10:47am

Thank you so much Rick,

Following your advice we tried different things and we could find the problem.
It turned out the DNS on the new servers couldn't retrieve IP addresses.
Fixing that issue fixed the error.
Also I got the same error when I had SSL certificat issue.
For instance our SSL certificate was not a wildcard certificate (*.xxxxx.net), it was setup for a specific domain name.

Thanks to you again.
Kathy

Gravatar is a globally recognized avatar based on your email address. re: SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Alejandro A Sosa
  Rick Strahl
  Apr 22, 2020 @ 02:07pm

Sorry this question is a little long.

I had the same problem as Kathy, but in my case it happened when I moved the SignalRSamples.sln where I had compiled SignalRClient.dll to a separate directory.

After looking at the dll with an editor and noticing there is a hard coded path to the SignalRClient.pdb file in there, I first placed a copy of SignalRClient.pdb next to SignalRClient.dll, but the problem persisted.

Then I placed a copy of SignalRClient.pdb to the hard coded path in an otherwise empty directory tree, but the problem persisted.

So, looking inside the SignalRClient.pdb file found there are a large number of hard coded references to source files.

After reading a little about pdb files the question is, is there a way of using SignalRClient.dll without the including the source files where .NET can find them?

Thank you very much.

Alex

Gravatar is a globally recognized avatar based on your email address. re: SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Rick Strahl
  Alejandro A Sosa
  Apr 22, 2020 @ 03:32pm

Uh, the .pdb file is the debug file - it's not used for actually running the application, all it does is provide extra error info when an exception occurs.

The sample application was just that - a sample application and if you want to use it as your base, you will have to change the URLs etc. It wasn't meant as a generic tool - it's an example of doing something very specific. If you want to use this you'll have to customize this to your own needs and put in your own resource links.

+++ Rick ---

Gravatar is a globally recognized avatar based on your email address. re: SignalR chat sample: OLE IDispatch exception code 0 from mscorlib
  Alejandro A Sosa
  Rick Strahl
  Apr 22, 2020 @ 06:02pm

Thank you, Rick.

Alex

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