The upload of a TCX File fails, if in the Author/Build Element the tags BuildMajor and BuildMinor are missing.
According to the the Garmin ActivityExtensionV2 Schema the Elements BuildMajor and BuildMinor are not required:
see https://www8.garmin.com/xmlschemas/ActivityExtensionv2.xsd
<xsd:complexType name="Version_t">
<xsd:sequence>
<xsd:element name="VersionMajor" type="xsd:unsignedShort"/>
<xsd:element name="VersionMinor" type="xsd:unsignedShort"/>
<xsd:element name="BuildMajor" type="xsd:unsignedShort" minOccurs="0"/>
<xsd:element name="BuildMinor" type="xsd:unsignedShort" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
Upload fails.
<Author xmlns:xsi="">www.w3.org/.../XMLSchema-instance" xsi:type="Application_t">
<Name>Polar Flow Mobile Viewer Android</Name>
<Build>
<Version>
<VersionMajor>0</VersionMajor>
<VersionMinor>0</VersionMinor>
</Version>
</Build>
<LangID>EN</LangID>
<PartNumber>XXX-XXXXX-XX</PartNumber>
</Author>
Upload succeeds:
<Author xmlns:xsi="">www.w3.org/.../XMLSchema-instance" xsi:type="Application_t">
<Name>Polar Flow Mobile Viewer Android</Name>
<Build>
<Version>
<VersionMajor>0</VersionMajor>
<VersionMinor>0</VersionMinor>
<BuildMajor>0</BuildMajor>
<BuildMinor>0</BuildMinor>
</Version>
</Build>
<LangID>EN</LangID>
<PartNumber>XXX-XXXXX-XX</PartNumber>
</Author>