Unable to login to Reseller WHM not associated to domain after upgrading to v92

Symptoms

After upgrading to v92 you're unable to login to WHM with a reseller that is not associated with a domain name based on our guide:

https://docs.cpanel.net/knowledge-base/accounts/how-to-create-a-whm-reseller-without-an-associated-domain/

Description

After upgrading to v92, you're unable to login to WHM with a reseller that is not associated with a domain name, you get the error:

Could not create Locale handle: Failed to load testreseller’s config file! (errno=) at /usr/local/cpanel/Cpanel.pm line 95.
:  at /usr/local/cpanel/Cpanel/Config/ConfigObj.pm line 741.
 at /usr/local/cpanel/Cpanel/Config/ConfigObj.pm line 741.
 Cpanel::Config::ConfigObj::get_locale_handle(Cpanel::FeatureShowcase=HASH(0x20f39a0)) called at /usr/local/cpanel/Cpanel/Config/ConfigObj.pm line 755
 Cpanel::Config::ConfigObj::fetch_meta_interface(Cpanel::FeatureShowcase=HASH(0x20f39a0)) called at /usr/local/cpanel/Cpanel/Config/ConfigObj/Interface/Config/v2.pm line 56
 Cpanel::Config::ConfigObj::Interface::Config::v2::meta(Cpanel::Config::ConfigObj::Interface::Config::v2=HASH(0x27a7390)) called at /usr/local/cpanel/Cpanel/FeatureShowcase.pm line 171
 Cpanel::FeatureShowcase::get_new_feature_showcase(Cpanel::FeatureShowcase=HASH(0x20f39a0)) called at whostmgr/bin/whostmgr3.pl line 350
 main::feature_showcase("feature_showcase") called at /usr/local/cpanel/Whostmgr/Dispatch.pm line 274
 Whostmgr::Dispatch::_do_call("feature_showcase", HASH(0x200f460), HASH(0x20312c8)) called at /usr/local/cpanel/Whostmgr/Dispatch.pm line 172
 Whostmgr::Dispatch::dispatch("feature_showcase", 14337, ARRAY(0x20016c0)) called at whostmgr/bin/whostmgr3.pl line 156

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-35056. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

Manually create /var/cpanel/users/$reselleruser

With the contents:

# cPanel -- If you edit this file directly you must run /usr/local/cpanel/scripts/updateuserdomains afterwards to rebuild the system caches.
# If you edit MAX_EMAIL_PER_HOUR or MAX_EMAIL_PER_HOUR-[domain] you must run /usr/local/cpanel/scripts/updateuserdomains'

LOCALE=en

Then run the command:

/usr/local/cpanel/scripts/updateuserdomains