P: Program error when saving, lag when zooming, changes not reflecting in document window (macOS)

Here are all the entries from PSErrorLog.txt from the day this error occurred for me:

2015:07:07 09:54:45 : /Volumes/workarea/PS_16_Mac_Daily_Retail/20150529.r.88/photoshop/main/photoshop/sources/UVMAccess.cpp : 778 : REQUIRE failed
2015:07:07 09:54:57 : /Volumes/workarea/PS_16_Mac_Daily_Retail/20150529.r.88/photoshop/main/photoshop/sources/UVMAccess.cpp : 778 : REQUIRE failed
2015:07:07 09:55:03 : /Volumes/workarea/PS_16_Mac_Daily_Retail/20150529.r.88/photoshop/main/photoshop/sources/UVMAccess.cpp : 778 : REQUIRE failed
2015:07:07 09:55:11 : /Volumes/workarea/PS_16_Mac_Daily_Retail/20150529.r.88/photoshop/main/photoshop/sources/UVMAccess.cpp : 778 : REQUIRE failed
2015:07:07 09:55:21 : /Volumes/workarea/PS_16_Mac_Daily_Retail/20150529.r.88/photoshop/main/photoshop/sources/UVMAccess.cpp : 778 : REQUIRE failed

Using Photoshop CC 2015, Mac OS X 10.10.3
Thanks

You have some errors from a third party automation plugin or extension panel, plus the last one is from something using a color mode that is not legal for layers (like indexed color). Resetting preferences should solve that, unless it is also being caused by third party code.

Here are the last few lines of a very long log:

\photoshop\main\photoshop\interfaces\UTrackResourceImp.h : 149 : REQUIRE failed
2015:01:16 12:22:11 : tracked key 00000000000000E0 of type struct _ADsc * __ptr64 not found : 1 : REQUIRE failed
2015:01:16 12:22:11 : e:\ps13\ps_13.1_win_x64_daily_retail\20131024.r.34\photoshop\main\photoshop\interfaces\UTrackResourceImp.h : 149 : REQUIRE failed
2015:01:16 12:22:11 : tracked key 00000000000000A8 of type struct _ADsc * __ptr64 not found : 1 : REQUIRE failed
2015:01:16 12:22:11 : e:\ps13\ps_13.1_win_x64_daily_retail\20131024.r.34\photoshop\main\photoshop\interfaces\UTrackResourceImp.h : 149 : REQUIRE failed
2015:01:17 12:26:26 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:01:20 13:42:48 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:01:20 13:43:34 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:19 09:17:35 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:21 18:03:38 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:21 18:04:56 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:25 22:59:26 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:25 23:00:53 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:25 23:01:37 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed
2015:06:25 23:02:16 : ..\..\sources\USheetSelection.cpp : 260 : REQUIRE failed

Thanks Josh. Really glad this is helping people out!

What are the last few lines in the PSErrorLog.txt file (in your Photoshop preferences folder)?

Don't think so. We have Red Hat and AFP, same issues.

Ah, yes. I was saving to a SMB (NTFS) server. Probably relevant.

I get this every once in awhile on Mac. I have always been able to save to a different hard drive. Quitting and relaunching the program then fixes it.

I also encounter this problem in Photoshop CC 2015, Mac OS X 10.10.3.

Unlike the OP I had not been merging any layers. I had been playing around with layer masks instead.

The 'switch to 16 bits and back' workaround worked for me thankfully.

Please fix this old bug Adobe.

You. Superstar.