plug-ins do not appear in Lightroom after installing. How do I fix this?
Occasionally, after running a Nik Collection installer, the software may not be installed correctly in Adobe Lightroom. This may occur because the “Store Presets with Catalog” option in Lightroom's Preferences is checked [on]. This option is in Edit > Preferences > Presets OR Lightroom > Preferences > Presets. Un-checking this box will make all of the plug-ins appear in the Photo > Edit In menu.
If the filters still do not appear in Lightroom then a manual installation may be necessary. 
To manually install one of the Nik Collection products after the installer has been run, please do the following:

1. 	Ensure all image editing applications such as Photoshop and Lightroom are closed.

2. 	Re-run the Nik Collection installer again, making sure that you've uninstalled all previous versions, and ensure the default install location is used (C:\Program Files\Google\Nik Collection OR Macintosh HD\Applications\Nik Collection). Note: In the install steps there is a window dialog where you can ADD programs to the install list- Check that you see both Photoshop and Lightroom in this dialog.

3. 	Open Lightroom again and look to see if the Nik Collection product is now installed under Photo > Edit In> [name of product]. If it does not appear to be installed, please continue to step 4.

4. 	While Lightroom is still open, click Edit> Preferences OR Lightroom > Preferences.

5. 	Click on the "External Editing" tab at the top of preferences.

6. 	Midway down on the right click on the [Choose] button and locate the Nik Collection application file you wish to add. 
Typically it can be found at either, C:\Program Files\Google\Nik Collection\Viveza 2\Viveza 2.exe, OR Macintosh HD\Applications\Nik Collection\Viveza 2\Viveza 2. For other products, replace Viveza 2 with the appropriate product.  

7. 	Once located, select the program or application file as indicated above and click "Choose". 
(Note: you may need to navigate to folders for 64bit versions)

8. 	Set the file format to "TIFF", Color-Space to sRGB (or the one of your choice), Bit Depth to 16-bit, Resolution to 240, and Compress to None.

9. 	At the end of the Preset box- click the drop down selector and choose, "Save Current Settings as New Preset" from the list.

10. 	Type in the name of the plug-in such as"Viveza 2" and click Create. Close preferences by clicking OK.

You may add another plug-in by going back and following steps 6 - 10 again, ignoring any preset you see listed in the ‘Preset’ box. 
The plug-in(s) you added should now be accessible. 

Please note, you do NOT want to do this with HDR Efex Pro 2. It is handled a different way than the other plug-ins. HDR Efex Pro 2 is accessible in Lightroom under File>Export with Preset.