Fatal Internal Error: "datatype.cpp", line 766

[ccmonter]

I received a 'Fatal Internal Error' that is not listed among the commonly encountered errors.

- LabView 7.1
- "datatype.cpp", line 766
- Windows 2000
- no 'LabVIEW_Failure_log.txt' found on c:\winnt\temp
- I have a vi that runs to completion. After execution is complete, any further action that I take (exiting LabView or checking the properties of a control) causes LabView to crash. Occassionaly, I will get the 'datatype line 766' error.
- I do not have a small ( < 50kb) VI that experiences the error. The vi that I am running is 305kb and uses subvis totalling 1.3MB.

Any assistance would be greatly appreciated.

[jpeters]

If you can pare the VI down and post it, I will be glad to take a look see.

Jeff Peters
LabVIEW R & D

[ccmonter]

Thanks for the offer.

I have been trying to isolate the error, but it has been very difficult as the errors are now quite erratic in nature. I only get the errors with this VI, and only when I am using the reporting functionality (writing to HTML).

However, the errors are now all over the map. Sometimes, LabView crashes with no warning. Other times, I get the "Fatal Internal Error", but with different modules specified.

I will try to append to this thread whenever I get a different error.

[jules849103]

Hi,
I have also the same problem. I am using some VIs from the version 6 on version 7.1 such as all the VIs concerning the ActiveX events. When I want to destroy an event queue, it seems that the Wait On Event is still running and does not want to stop. The most beautiful is that I have two types of event queue, and only one is doing this fatal error, the other is destroyed without any problems...
Any ideas?
bye julien

[Caroline Bright]

Hello Julien,

I have been researching into your issue and I have a few suggestions. First, this crash could be happening because somehow you are destroying that event structure before the Wait on Event. The wait may then be looking for an event that no longer exists. I would run through the program in highlight execution so that you can see exactly what happens in what order.
Also, there have been reported problems with these vis in older versions of LabVIEW. It sounded like from your post that you are using the vis from version 6 running in version 7.1. Can you try to substitute these vis with the newer ones to see if this solves the problem.
Finally, if this does not work, you can post a small portion of your code that illustrates the problem so that I can recreate the problem here.

Thanks,
Caroline
National Instruments

[jules849103]

Hello Caroline,
It is pretty nice to answer my message. I have several remarks about your answer. I know that it exists a function Reg Event Callback which looks like very useful to implement the activeX event. But, I have already tried to use it, and the GeneralEvent (event which returns only a string) are well "catched", but the others events ( MessageEvent: event which returns a Boolean bSuccess, and a reference to an object) does not work at all. So I am obliged to work on older vis because it works.
I will try to explain you exactly what is the problem:
I am doing a program with labview in order to control a device linked to my computer via Ethernet, and thus 3 kind of automation objects were created: Application, Project and Message.
The application object can open, close... an application which will interface between the device and my computer. The project object will open a project inside this application. And finally, the message object will send, receive message from/to device to/from the computer.
The application can get two kinds of events: GeneralEvent and MessageEvent. The general event gives you a description of what have been done on the device. The message event gives you a boolean bSuccess and a reference to a message that the computer received.
With RegEventCallback the general events are well catched but nothing appears to the message event, but i know that a message event was received due to the general event...
So the question is: is it possible that an incompatibility from labview and my activex objects occurs?
Ok, I am sorry, but I cannot give you even a part of my code...
thanks julien

[jules849103]

You will find here the error, that I get with the Wait On ActiveX Event:

[Caroline Bright]

Hello Julien,

I believe that the problem we are seeing is from vi compatibilities because of the LV version change. Our vis sometimes change as a new version is created to respond to customer needs. I think that the best thing to do is try this program on versions between 6 and 7.1 to try and find the problem. If you have these versions, please try you program on them and let me know any errors you receive. If you do not have them, you can download an evaluation version of LV 7 from:
http://digital.ni.com/demo.nsf/websearch/14F9CE475127ADE786256AC60070926C?OpenDocument&node=157200_US
Let me know any errors that you receive.

Thanks,
Caroline
National Instruments

[earth1111]

Hi

I keep getting the error datatype.cpp Line 766 whenever I try ot finishi this VI. I have tried on three different machines, with 7.1 and 7.1.1.

Open sub Test.vi and it will be broken because I left  a case structure output unwired.

Try to clear the error and save and it will crash with error data.type.cpp

HELP!!!!!!!!!!!!!!!!