Makeappx bundle in Windows: The filename, directory name, or volume label syntax is incorrect

[sairus7]

When I run command to create bundle

makeappx pack /d EcgReview-x64 /p EcgReview-x64.msix /v

The following error appears:

Settings for extension md: Type = application/octet-stream, Compression = Normal.
Processing "\\?\C:\Build\EcgReview-x64\packages\FilePathsBase\docs\src\faq.md" as a payload file.  Its path in the package will be "packages\FilePathsBase\docs\src\faq.md".
Settings for extension svg: Type = image/svg+xml, Compression = Normal.
Processing "\\?\C:\Build\EcgReview-x64\packages\FilePathsBase\docs\src\hierarchy.svg" as a payload file.  Its path in the package will be "packages\FilePathsBase\docs\src\hierarchy.svg".
Settings for extension md: Type = application/octet-stream, Compression = Normal.
Processing "\\?\C:\Build\EcgReview-x64\packages\FilePathsBase\docs\src\index.md" as a payload file.  Its path in the package will be "packages\FilePathsBase\docs\src\index.md".
MakeAppx : error: For file "\\?\C:\Build\EcgReview-x64\packages\FilePathsBase\docs\src\index.md" - Failure at opcFactory->CreateStreamOnFile(longFilePath, ioMode, NULL, FILE_ATTRIBUTE_NORMAL, fileStream) - 0x8007007b - The filename, directory name, or volume label syntax is incorrect.
MakeAppx : error: Failure at (hr) - 0x8007007b - The filename, directory name, or volume label syntax is incorrect.
Cleaning up output file "\\?\C:\Build\EcgReview.msix".
MakeAppx : error: Failure at (CreatePackage( overwrite, hashAlgorithm, fileList, outputPath, manifestStream.Get(), forceCompressionNone, performanceOptions, encryptPackage, encryptionOptions, cgmPath, mainPackagePathForResourceExemption, makepriExeFullPath, publisherBridgingList)) - 0x8007007b - The filename, directory name, or volume label syntax is incorrect.
MakeAppx : error: Package creation failed.
MakeAppx : error: 0x8007007b - The filename, directory name, or volume label syntax is incorrect.

Any ideas why?

[sairus7]

Strange, I have deleted that single index.md and bundle creation succeed.

[JanisErdmanis]

I have no idea. It would be interesting to see if you add back the index.md file if it still fails. Also on windows one should not take some sane assumptions for granted. It is worth to:

• Check if renaming original index.md to lets say renamed-index.md has the same issue;
• Check what happens if index.md is being moved in a different folder;
• If you delete original index.md and replace with a new one, check if the issue persists;