Thanks Wolfgang. I had tried \# which I normally use to escape a hash but it didn't work. I was unaware of \letterhash.

On 19 Dec 2021, at 17:37, Wolfgang Schuster wrote:

Bruce Horrocks via ntg-context schrieb am 19.12.2021 um 18:12:

...

Hi,

The following MWE won't compile for me:

\setupinteraction [state=start] \starttext Click me: \goto{https://forum.swissmicros.com/viewtopic.php?f=2&p=22236#p22236} [url(https://forum.swissmicros.com/viewtopic.php?f=2&p=22236#p22236)] \stoptext

under "mtx-context | current version: 2021.12.10 11:41"

\useURL fails as well so I assume it's in the URL parser.

The hash (#) is a special character in TeX and you have to either replace it with something safe like \letterhash or in case of \useurl you can put all settings in a asciimode block, e.g.

\startasciimode \useurl [...] \stopasciimode

Wolfgang

— Bruce Horrocks Hampshire, UK