Reproducible Bug with WebDAV and reading system time from the cRIO.

[GregFreeman]

Update: Unable to reproduce in LV 2023, but 2018 seems to still have the issue.

I had posted this in the Champions Forum but now that I have a minimally reproducible example, I'm posting here for more visibility. I am using LabVIEW 2018 with a 9047 cRIO.

Steps to reproduce.

First:

1. Use some method to create a test file called test.dat on the rio in the home/lvuser directory. I used WinSCP, but I'm assuming filezilla would work as well as just ssh-ing in and creating a file in that directory
2. Open the VI attached to this post.
3. Update the IP addresses for your RIO.
4. Leave the disabled case disabled for now
5. Run the VI. You should get error 363503

Error 363503 occurred at an unidentified location

Possible reason(s):

LabVIEW: (Hex 0x58BEF) The HTTP client-side libraries (or one of its dependencies) failed to load.

Second:

1. Enable the currently disabled case so that we now use webdav once before we read the system time.
2. Save the VI with this case enabled
3. Run the VI -- you should still get error 363503.
4. Ensure VI is saved with this case still enabled. Completely close LabVIEW
5. Re-open LabVIEW and open the VI again and run. It should now succeed.
6. Disable the enabled case so now we do not use WebDAV before reading the system time.
7. Run the VI -- It will continue working now.
8. Save the VI
9. Close LabVIEW and reopen -- it will be back to not working.

It seems there is something go on where reading the system time from the RIO before accessing anything with WebDAV will cause the WebDAV VIs to stop working. However, if webdav is accessed first, the problem seems to be non-existent for the duration LabVIEW is opened. Same in reverse -- if the error appears, the error will remain for the duration of your LabVIEW session.

I am curious if others can reproduce this problem. 

[elcalverado]

Just tried this in LabVIEW 2020 and no error on the first run of the VI with the section disabled.

[GregFreeman]

Any chance you can attempt with 2018? It's reproducible on my coworkers pc as well as mine. It may have been fixed since then but I don't have any labview versions installed other than 2018 and 2023

[Nick-W]

I am seeing similar error just calling WebDAV VIs on my dev to sbRIO-9651.  Errors from LV 2018,and 2019, but passes from 2020 or 2023 - all same system.  Seems to have broken after installing LV 2023 Q3.