Can't change to a new photo in Develop Module

For the past several weeks I occasionally have the Develop module get stuck on one photo. I believe it happens when I move over to Library to do some things, then come back to start editing new photos. I can progress through photos in Library but when I try to click on develop to edit a photo, it just shows the photo from my previous editing session and won't move off that.  The only solution I have found is to restart Lightroom. Then it starts working again.  I read there was a problem with LR crashing when switching from Library to Develop, but mine is not really crashing. None the less I checked out one of the solutions which was to Select Preferences > Performance and deselect Use Graphics Processor. I found that my check box was already deselected, so that does not appear to be the issue.

I realize I need to start another thread for this but in case it ties in with this problem, just today I also started have trouble with my crop tool.  The crop box will appear in whatever dimension I specify, but the box cannot be moved or changed in size.  Maybe my whole system has become corrupted somehow?

I'm in Lightroom CC. Below is some info from my system if it helps.

Thanks,

Lisa

Lightroom version: CC 2015.8 [ 1099473 ]

License: Creative Cloud

Operating system: Mac OS 10

Version: 10.12 [5]

Application architecture: x64

Logical processor count: 4

Processor speed: 2.9 GHz

Built-in memory: 8,192.0 MB

Real memory available to Lightroom: 8,192.0 MB

Real memory used by Lightroom: 299.1 MB (3.6%)

Virtual memory used by Lightroom: 3,513.5 MB

Memory cache size: 834.2 MB

Maximum thread count used by Camera Raw: 4

Camera Raw SIMD optimization: SSE2,AVX

Displays: 1) 1680x1050

Graphics Processor Info:

Check OpenGL support: Failed

Vendor: Intel Inc.

Version: 4.1 INTEL-10.25.13

Renderer: Intel HD Graphics 4000 OpenGL Engine

LanguageVersion: 4.10