I think you can enable the debugging to have more details of what's sent to the Wikibase instance, you can follow instructions at the end of the README: https://github.com/LeMyst/WikibaseIntegrator/blob/master/README.md#debugging
You should see some debug message starting with "DEBUG:wikibaseintegrator.wbi_helpers", with the token size.

Hello @megamattc ,
Do you still have the issue? Do you have a stacktrace of the issue?

After more tests, using the latest version for Gitlab branch REL1_35 (b697ceb) seem to solve the issue.

After some tests, I can reproduce the same error message when I try to create an OAuth "2.0" consumer (work correctly with 1.0a).
For me, the issue come from line https://github.com/wikimedia/mediawiki-extensions-OAuth/blob/e9e921dbd4ef948fd260a8560ddd035add543f7a/src/Frontend/SpecialPages/SpecialMWOAuthConsumerRegistration.php#L314

In T189879#4656660, @TheDJ wrote:

@Myst

"https://nominatim.openstreetmap.org/search?format=json&q={s}" by "https://tools.wmflabs.org/nominatim/search"

That should be https://tools.wmflabs.org/nominatim/search?format=json&q={s} in that case.
I fixed the double encoding issue and I also added rate limiting.

In T189879#4653294, @TheDJ wrote:

Endpoints:
https://tools.wmflabs.org/nominatim/search
https://tools.wmflabs.org/nominatim/reverse
https://tools.wmflabs.org/nominatim/lookup

Repo:
https://phabricator.wikimedia.org/diffusion/2416/

Still needs some cleanup and a HTML page to explain itself, but it's a start.

Tool updated without Google dependencies.
Only OSM dependency now:
https://tools.wmflabs.org/coord/