Flash movie with full screen mode does not work.
(the flash frame turns to be blank.)

I confirmed this problem occurs: https://www.permadi.com/tutorial/flash9FullScreen/index.html
https://student.testmasters.com/portal/online/Test.aspx

I want to know this problem can be reproduced on other Macs, or not.

Version

Opera: 55.0.2994.37
Flash: 30.0.0.154
OSX: High Sierra (10.13.6), Yosemite (I updated my OSX, but this problem was not resolved.)
Laptop: MacBook Air Mid 2012, Intel HD Graphics 4000 1536 MB
(I concern my MBA is a bit old model and so this problem occurs.)

Other Browsers

Firefox, Chrome, and Safari work fine.
Opera for windows (on my own other PC) works fine.

I also tried:

• disable/enable hardware acceleration of flash and opera
• disable/enable 'Predict network actions to improve page load performance' (cf: https://forums.opera.com/topic/19441/full-screen-issue/5)

I found some warnings on the gpu log, this might be related.
opera://gpu/ :

Graphics Feature Status
Canvas: Software only. Hardware acceleration disabled
Flash: Software only. Hardware acceleration disabled
Flash Stage3D: Software only. Hardware acceleration disabled
Flash Stage3D Baseline profile: Software only. Hardware acceleration disabled
Compositing: Software only. Hardware acceleration disabled
Multiple Raster Threads: Disabled
Native GpuMemoryBuffers: Software only. Hardware acceleration disabled
Hardware Protected Video Decode: Disabled
Rasterization: Software only. Hardware acceleration disabled
Skia Deferred Display List: Disabled
Skia Renderer: Disabled
Surface Synchronization: Disabled
Video Decode: Software only. Hardware acceleration disabled
Viz Service Display Compositor: Disabled
WebGL: Disabled
WebGL2: Disabled
Problems Detected
GPU process was unable to boot: GPU process crashed too many times with SwiftShader.
Disabled Features: all
Viz service display compositor is not enabled by default.
Disabled Features: viz_display_compositor
Skia renderer is not used by default.
Disabled Features: skia_renderer
Skia deferred display list is not used by default.
Disabled Features: skia_deferred_display_list
Version Information
Data exported	2018-08-18T16:49:42.357Z
Browser version	OPR/55.0.2994.37
Operating system	Mac OS X 10.13.6
ANGLE commit id	unknown hash
2D graphics backend	Skia/68
Command Line	/Applications/Opera (1).app/Contents/MacOS/Opera --flag-switches-begin --disable-features=SharedArrayBuffer --flag-switches-end --use-turbo2 --prefer-integrated-gpu --enable-quic
Driver Information
Initialization time	0
In-process GPU	true
Passthrough Command Decoder	false
Direct Composition	false
Supports overlays	false
Sandboxed	false
GPU0	VENDOR = 0x0000, DEVICE= 0x0000
Optimus	false
AMD switchable	false
Driver vendor	
Driver version	
Driver date	
Pixel shader version	
Vertex shader version	
Max. MSAA samples	
Machine model name	
Machine model version	
GL_VENDOR	
GL_RENDERER	
GL_VERSION	
GL_EXTENSIONS	
Disabled Extensions	
Disabled WebGL Extensions	
Window system binding vendor	
Window system binding version	
Window system binding extensions	
Direct rendering	Yes
Reset notification strategy	0x0000
GPU process crash count	0
Compositor Information
Tile Update Mode	Zero-copy
Partial Raster	Enabled
GpuMemoryBuffers Status
ATC	Software only
ATCIA	Software only
DXT1	Software only
DXT5	Software only
ETC1	Software only
R_8	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
R_16	Software only
RG_88	Software only
BGR_565	Software only
RGBA_4444	Software only
RGBX_8888	Software only
RGBA_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
BGRX_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE
BGRX_1010102	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
RGBX_1010102	Software only
BGRA_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
RGBA_F16	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
YVU_420	Software only
YUV_420_BIPLANAR	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
UYVY_422	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
Display(s) Information
Info	Display[69680128] bounds=[0,0 1440x900], workarea=[0,23 1440x877], scale=1, external.
Color space information	{primaries_d50_referred: [[0.5932, 0.3496], [0.3542, 0.5676], [0.1589, 0.1043]], transfer:0.0777*x + 0.0000 if x < 0.0450 else (0.9478*x + 0.0521)**2.4000 + -0.0000, matrix:RGB, range:FULL}
Bits per color component	8
Bits per pixel	24
Video Acceleration Information
Log Messages
[1291:775:0819/014235.802852:ERROR:gl_implementation.cc(292)] : Failed to load /Applications/Opera (1).app/Contents/Versions/55.0.2994.37/Opera Framework.framework/Versions/Current/Libraries/libswiftshader_libGLESv2.dylib: dlopen(/Applications/Opera (1).app/Contents/Versions/55.0.2994.37/Opera Framework.framework/Versions/Current/Libraries/libswiftshader_libGLESv2.dylib, 1): no suitable image found. Did find: /Applications/Opera (1).app/Contents/Versions/55.0.2994.37/Opera Framework.framework/Versions/Current/Libraries/libswiftshader_libGLESv2.dylib: file system sandbox blocked stat()
GpuProcessHostUIShim: The GPU process exited with code 1024.

I can provide any more detail information if needed.