NetWitness provides metadata items derived from headers in the HTTP/2 stream after append HTTP2="headers=true" (or HTTP2="headers=true extract=all" in 12.x version) to /decoder/parsers/config/parsers.options.
But some users can't see the metadata (for example: action, alert, alias.host, directory, referer) from HTTP2 sessions after configure the parser options.
Below image is the example whichdoesn't have HTTP2 metadata. Image description
Below image is the example which have HTTP2 metadata. Image description
A possible case is there is a typo with the double quotes (") in Explore view for where the HTTP/2 Metadata options were entered. The double quote (") character in some non-English keyboard layouts is similar, but slightly different.
Go to ADMIN > Services and select a Decoder, and in the actions menu, select View > Explore.
Expland decoder > parsers and select config.
In parsers.options, check and correct the double quote (") character of HTTP2="headers=true".
In the left panel, right-click parsers and click Properties. In the drop-down menu, select reload and then click Send.