For reference, I am using LabVIEW 2017 SP1 on a Windows 10 machine.
I recently inherited a large LabVIEW project which uses quite a few PPLS (approx. 20). Many of these PPLs have dependencies on others. From what I can tell it is never a two-way street (i.e. where two PPLs both call VIs from each other), but there are hierarchal relationships between them. They are ultimately all used in this top-level project.
I ran into an interesting issue with this and was hoping the community might have more info/guidance - keep in mind I've never used PPLs before but have been doing quite a bit of reading on them. I do seem to have solved the issue and wanted to share what info I have as well.
Initially I was building these PPLs in various individual locations, then moving them to a common folder. This common folder was then included in my top-level project for use. When building say, PPL B with a dependency on PPL A, I would reference the copy of PPL A that was in this common folder. Thus all builds that required any PPLs would use this common location. However this seemed to cause a couple different and odd issues:
- Some (seemingly random) VIs within the PPLs could not be found in the top-level project. I would be able to see the PPL in the project and the VIs in question, but they would show up under dependencies as having been deleted or moved on disk. I tried replacing these dependencies with the files explicitly, but they would simply reappear under dependencies. I'd be able to build an exe, but when running it would not be able to find these VIs.
- Issues generating an exe preview. I'd be able to build an exe no problem, but when I'd try to generate a preview I'd get error 7. This is similar to issue 1 - it would be unable to find a particular VI within one of the PPLs. The interesting thing with this issue is that if I closed LabVIEW entirely and reopened the project, I'd be able to successfully generate an exe preview exactly once before the issue would resume. All without making any actual changes within the project.
Ultimately I was able to solve this by building the PPLs directly into the common folder location. Why is this necessary though? I would think that if they ultimately end up in the same location with their dependencies, they'd be able to find everything...but clearly this wasn't the case. It also seems very strange that it's only a handful of seemingly random files that had problems.
If anyone has any insight on this I would be very interested. Happy to provide more info if needed as well.
