How to debug "Object reference not set to an instance of an object" error message on Test Stand close

[IvanZj]

Hello all,  
I'm evaluating if our sequence files created using TestStand 2016 are compatible on latest Test Stand. 
I keep seeing "Object reference not set to an instance of an object" popup message when closing the application. Screenshot attached.  
I suspect that this is somehow related to sequence file conversion from older TS to newer, but I have no idea where to look. Is there any log file to which Test Stand is logging more verbose messages? I checked event viewer and as it seems, there are no Test Stand related logs.  

Sequences often use .net adapters. We don't use LabView or similar adapters  

workflow: 
1. Use Sequence file converter converter to convert all files from format version 16 to format version 23

2. Open TestStand (using env flag and custom "start in" path with specific folder where sequence files are stored)

3. Open sequence file. 

4. Close

5. Errors: 

5.1

5.2 

 

6. Start plain SeqEdit.exe, without env flag., no custom process model is loaded

7. Close
8. Error same as in 5.1, but without 5.2

Doing same set of steps using TS2016, using same sequence files don't trigger any error

How to troubleshoot this?

Thank you

[Oli_Wachno]

I suggest to first chech the actual error message, which gives you the top level objects.

Can you share the full path?

[IvanZj]

sorry about that, it is: AppData\Local\National Instruments\TestStand 2026 (64-bit)\SeqEdit.xml    
I tried to delete it, but nothing id changing

[Oli_Wachno]

Don't know, if this really matters....but maybe worth asking: is TS2016 32 or 64 Bit?
If it is 32 Bit, have you tried to import the old seq files with the currenct 32Bit version?

[IvanZj]

Both are 64 bit

[Scott_Richardson]

That file is what is saved when configuring the Sequence Editor settings. I suspect that either this is a bug in the Sequence Editor, or something is occurring on shutdown that is causing the process to incorrectly shutdown and it fails to release that file. If you delete the file, I believe that the Sequence Editor will generate one with defaults on the fly.

The only thing I can think of is to determine what actions in the Sequence Editor make this dialog appear and try to figure out if there is anything you are doing that might affect that file reference, unlikely.

If this is the only file leaking, it is a bounded leak and likely can be ignored. FWIW, you can turn off displaying this dialog using Configure>>Station Options>>Preferences Tab>>Debug Options>>Report Object Leaks.

[Scott_Richardson]

Thinking about this more resulted in a few more thoughts:

1. I suspect that there is something about your converted file and displaying it in the Sequence Editor panes that is causing the object reference error and that contributes to the leak(s) when using an env, so I would target the error.
2. The error might be due to some internal exception when the Sequence Editor displays the steps in the first displayed sequence. Add an empty sequence at the top of the list in the file and save. Exit the Sequence Editor and reopen the saved file with the empty sequence being displayed first and exit, does the error occur?
3. How many sequence and steps do you have in each?
4. Do you have any custom step types that you are using? If yes, do any of the step types use any unique step description expressions?
5. Not sure if the ROI will be high enough but if you wanted to determine what in the file might be causing the issues you could start deleting portions of the file and save, then restart the Sequence Editor and reload and exit to see if the object reference issue occurs. This might tell you what part of the file that might be contributing to the issue.