This is not an error that I have any experience with.
Code:
2015-04-17 12:38:34, Info CBS Loading offline registry hive: SOFTWARE, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/SOFTWARE' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\SOFTWARE'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: SYSTEM, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/SYSTEM' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\SYSTEM'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: SECURITY, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/SECURITY' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\SECURITY'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: SAM, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/SAM' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\SAM'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: COMPONENTS, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/COMPONENTS' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\COMPONENTS'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: DEFAULT, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/System32/config/DEFAULT' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\System32\config\DEFAULT'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: ntuser.dat, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Users/default/ntuser.dat' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Users\default\ntuser.dat'.
2015-04-17 12:38:34, Info CBS Loading offline registry hive: schema.dat, into registry key '{bf1a281b-ad7b-4476-ac95-f47682990ce7}GLOBALROOT/Device/HarddiskVolumeShadowCopy29/Windows/system32/smi/store/Machine/schema.dat' from path '\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\system32\smi\store\Machine\schema.dat'.
2015-04-17 12:38:34, Info CBS Offline image is: read-only
2015-04-17 12:38:34, Info CBS Disabling manifest caching, because the image is not writeable.
2015-04-17 12:38:35, Error CSI 0000000e (F) STATUS_MEDIA_WRITE_PROTECTED #971439# from Windows::Rtl::SystemImplementation::DirectFileSystemProvider::SysSetInformationFile(flags = (AllowNotSameDevice), h = 5bc ("\Device\HarddiskVolumeShadowCopy29\Windows\winsxs\ManifestCache\a786a517e28d5687_blobs.bin"), iosb = @0xd1d8a0, buff = @0x255940, bufflen = 244 (0x000000f4), ic = 10 (0x0000000a), disp = Invalid)
[gle=0xd00000a2]
2015-04-17 12:38:35, Error CSI 0000000f@2015/4/17:16:38:35.085 (F) d:\win7sp1_gdr\base\wcp\sil\merged\ntu\ntsystem.cpp(2530): Error STATUS_MEDIA_WRITE_PROTECTED originated in function Windows::Rtl::SystemImplementation::DirectFileSystemProvider::SysSetInformationFile expression: (null)
[gle=0x80004005]
2015-04-17 12:38:38, Error CSI 00000010 (F) STATUS_MEDIA_WRITE_PROTECTED #971437# from Windows::Rtl::SystemImplementation::CSystemIsolationLayer_IRtlSystemIsolationLayerTearoff::TransferFile(flags = (ReplaceIfExists|OpenForBackupIntent|MissingFileIsOk), op = [4]"Move", odir = NULL, oname = [l:208{104}]"\??\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\WinSxS\ManifestCache\a786a517e28d5687_blobs.bin", ndir = NULL, nname = [l:220{110}]"\??\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\WinSxS\ManifestCache\a7c4a7f22c79d001020000000c1a1c17", disp = (null))
[gle=0xd00000a2]
2015-04-17 12:38:38, Error CSI 00000011 (F) STATUS_MEDIA_WRITE_PROTECTED #971428# from ComponentStore::CRawStoreLayout::RenameAwayManifestCacheBlobfileAttempting to RenameAwayManifestCacheBlobfile. Current blobfile name: [l:52{26}]"a786a517e28d5687_blobs.bin"
[gle=0xd00000a2]
2015-04-17 12:38:38, Error CBS Failed to get offline CSI store. [HRESULT = 0x80070013 - ERROR_WRITE_PROTECT]
2015-04-17 12:38:38, Error CBS Failed to initialize store parameters with boot drive: T: and windows directory: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy29\Windows\ [HRESULT = 0x80070013 - ERROR_WRITE_PROTECT]
I'll have to do some research and get back to you - probably tomorrow.