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classy datalogs, upgrading, and error 1401

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I'm getting error 1401 when trying to read datalogs that I created in 8.20. These datalogs were fine until I upgraded to 8.2.1 and mass-compiled.

"Error 1401 occurred at Read Datalog in SG.lvlib:toplevel_read_datalog.vi

Possible reason(s):

LabVIEW: Attempted to read flattened data of a LabVIEW class. The version of the class currently in memory is older than the version of the data. You must find a newer version of the class to load this data."

Note, I am always running my VIs from the development environment, both when creating datalogs and when reading them. When I create new datalogs I can read them; it's just the older datalogs that Labview thinks contain a newer version of the class. :headbang:

Any workarounds? Can I brute-force an uptick in the version number of my class, by going to its properties and just typing in a new version number, and if so do you think that would help? Should I change the data in my class in some subtle harmless way (I32 to U32?) to cause a version number increase? I'm a total GOOP novice, and I don't want to f mess things up any more than they already are.

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I have got the same error when I went from 8.2 to 8.2.1. So it may be an upgrade bug.

It was not a big problem for me since it was just the beginning of my project and there was no release yet. So I just use the new datalogs created in 8.2.1.

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  • 4 weeks later...

NI confirms: this is a bug, but they say that it will not happen on the next upgrade. They wrote to me:



I've investigated the bug report you filed. Please be assured that this is definitely a bug, and one I took very seriously. I want to assure you that the version-to-version support is supposed to be there and should be expected. Here is the situation:

If the file was written by: then:

1) 8.2 Only 8.2 can ever read that file, and sometimes not even

8.2 can read its own files. There was a corruption bug when

writing some types of data.

2) 8.2.1 All versions (8.2, 8.2.1 and 8.5) can read the data.

3) 8.5 All versions (8.2, 8.2.1 and 8.5) can read the data

The next version will have the backward compatibility that you sought.

I gave up on my old files; they weren't all that vital. Like you, I wasn't far from the beginning of my project.

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