Corrupted or Not Readable LLB in LabVIEW

Issue Details

LabVIEW gives one of the following errors when I try to open a LabVIEW library file (LLB): 

Error has occurred when listing the contents of <LLB file>.

Or:

<LLB file> is not a readable LLB. 



How can I recover my LLB files?

Solution

You can find the decorruptor.llb utility attached, in some cases it will fix the corrupt LLB.

Note: The compression used to store VIs in LLBs changed between 2014 and 2022 so this tool can fail to recover the files.

In order to use the decorruptor utility, you can follow these steps:

1. Create a new folder for the recovered files. 
2. Open LLB decorrupter.vi. 
3. On the Front Panel, browse to the corrupted LLB  in the corrupt LLB control and to the folder created for the recovered files in the destination directory control.
   
4. Run the VI. 
5. Any files that are able to be recovered will be moved to the new folder. It is possible that no VI in the library will be able to be recovered.

If the utility cannot recover the files, another option would be to contact NI Support and share the LLB with them, they would likely need to manipulate the LLB resource file format.

Note: There is no guarantee that NI Support will be able to recover all the files.

Additional Information

LLBs can become corrupted, typically because of a problem during the save process. It is recommended to use LLBs only for compact storage and file transport, but development efforts should use directories of VIs to mitigate corruption issues. It's strongly recommend to keep backup copies during development and consider using source code control options.