RsLogix 500 - Allen Bradley RsLinx Harmony Files. Deleting to Fix Browsing Issues
If you are having trouble browsing RsLinx such as yellow question marks where known PLCs used to be then the harmony files that sore the cache files of RsLinx have become corrupted.
If you work with RsLinx for any amount of time then you will eventually run into problems with the harmony files. In most occurrences you begin to run into trouble browsing the RsWho section of RsLinx in either the native program or in RsLogix.
There are two files, harmony.hrc and harmony.rsh, that must be deleted to fix it. Don't worry, they will be recreated when you open RsLinx.
1. Close RsLinx
2. Locate the harmony.hrc and harmony.rsh files
If you are using a 32 bit version of Windows then navigate to C:\Program Files\Rockwell Software\RSCommon.
If you are using a 64 bit version of Windows then navigate to C:\Program Files (x86) \ Rockwell Software\RSCommon1.
3. Delete the harmony.hrc and harmony.rsh files. If RsLinx or any program that uses RsLinx such as RsLogix are open then you will receive an error message saying "Cannot delete Harmony: It is being used by another person or program." Make sure these programs are closed and try again.
This will fix 99% of browsing problems in Rockwell Automation's RsLinx. Don't worry about loosing anything by deleting the harmony.hrc and harmony.rsh files. It is the same as clearing your browser cache.