Dear Rich and WeatherCat Davis station owners,
Thanks:
The extension I am running is 2.9.0d1 dated 5/20/2011.
Now I did find some corruption on my HD and spent most of today cleaning that up, and everything seems to be running fine once again.
As strange as it sounds, this older driver still seems to be working fine even in El Cap?
Not sure I want to mess with it.
Any thoughts would be appreciated.
Unfortunately, the only clear aspect of this situation is uncertainty. Silicon Labs released a new version of the driver this year, so long after Apple released El Capitan. You can read the release notes here:
http://www.silabs.com/Support%20Documents/Software/Mac_OSX_VCP_Driver_Release_Notes.txtI had thought the release notes had not changed, but this isn't true. It clearly states that the latest release was on February 15, 2016 and what was changed in that release (and I quote:)
Version 4.x.7
Added VID/PID for Sekonic and DASCOM.
Minor fix to postflight script for 64 bit 10.8 and below OS's.
That clearly is a fix and it does explicitly mention adjusting the support for Mountain Lion and earlier versions of OS X. Why on earth is Silicon Labs not acknowledging that this driver does work on El Capitain? After all, many WeatherCat users have been using it (and indeed earlier versions of the driver) on El Capitain without problems.
It is one of the reasons I've decided to stay at Yosemite for the moment. Better the devil you know than the devil you don't.
Sorry, that's all the wisdom I've got on the subject.

Edouard