Windows Explorer Preview not working sometimes

[Jeff C 0]

I'm using Nitro Pro 12.0.0.112 (on on Win 10 Home v. 1803, OS Build 17134.376). I am having a problem where sometimes a selected pdf file is not being previewed in Windows Explorer.  The preview pane has not been closed. Nothing shows in the preview area, not even message that a preview cannot be displayed. When this happens, selecting other pdfs does not help. This also seems to corresponds with Excel not being previewed at that time either. Sometimes closing out of Windows Explorer and restarting helps restore preview functionality. Any guidance on what the cause and solution is? Thanks

[AllainU 0]

Hello @Jeff C,

Thank you for reaching out to us through our Community Forums!

Let us try some troubleshooting by referring to these steps:

1. Run a repair on Nitro Pro. You may refer to this article: http://kb.gonitro.com/knowledgebase#/search/repair/000001641
2. Re-register the DLL file using the following Administrator command (Admin CMD): 

For 32-bit:
regsvr32 -u "C:\Program Files (x86)\Nitro\Pro\12\NitroPDFPreviewHandler.dll" 
regsvr32 "C:\Program Files (x86)\Nitro\Pro\12\NitroPDFPreviewHandler.dll" 

For 64-bit:
regsvr32 -u "C:\Program Files\Nitro\Pro\12\NitroPDFPreviewHandler.dll" 
regsvr32 "C:\Program Files\Nitro\Pro\12\NitroPDFPreviewHandler.dll"

Thank you very much in advance and I am looking forward to hearing back from you.