I am now back in office, and plan to look at this, ideally during this week. I think I can do it by using our own simulation server, and either block the execution by placing breakpoints in it, or adding "wait" commands to it at specific places.

Do you have an idea where precisely the problem occurs? It can be, for example
a) in the COM CreateInstance call for the OPCServer object
b) in some "ceremony calls" we do, for example, GetStatus on the OPCServer, or Advise (for the IOPCShutdown)
c) in the actual browsing call
Have you tried to put an OPC Analyzer in the middle, to figure out where it blocks? If not, can you do that, to reduce the number of things I have to try on my side?

Do you know whether the browsing method is OPC-DA 1.0, 2.x or 3.x?

Can you confirm that this happens:
1. Initial state - no EasyDAClient method have been called yet.
2. You start by calling BrowseBranches on the "bad" server
3. It times out after cca 20 seconds (please send me the exception message and details - it is really important)
4. You call BrowseBranches on a "good" server
5. It succeeds but it takes unnecessarily long (cca 20 seconds).

Best regards

Emilio,
I will look at this-please wait till next week.

OK, let's do it this way.

Before that - have you tried the same using some other simple OPC client? If they all do it, the problem may be somewhere in the system, and it would be pointless (although interesting) to try to hunt for it inside QuickOPC.

Best regards

Emilio,
I agree that it is weird.

Are both the good and the bad server on the same computer? If so, couldn't it be that there is something in the COM/DCOM which the "bad" server keeps locked or busy, and that affects the "good" server as well?

Can you try browsing the "bad" server, and then a "good" server on a different computer?

Obviously it can also be something inside QuickOPC, but it is difficult to tell without having a reproducible case. The idea of the browsing code is that once the first method is finished, the second execution (for the "good" server) should not be influenced by previous operations.