Error on Login Page

Support intro

Hi,

right know im facing the problem that I’m not able to login into my Webinterface of Nextcloud.
WebDAV works fine.
When I try to login into the Webinterface I get an internal server error.
Below you can see the log snippet.

Do you have any suggestions on how to fix this?
After the upgrade to Nextcloud 16 everything worked fine, but a few days later this error comes up…

Nextcloud version : 16.0.1
Operating system and version : Ubuntu 18.04
Apache or nginx version : Apache 2.4.29
PHP version : 7.3.6

The output of your Nextcloud log in:
{
“reqId”:“yt2mnfK7WCijKP1v4sRa”,
“level”:3,
“time”:“2019-06-11T20:56:40+00:00”,
“remoteAddr”:"<my_ip>",
“user”:"–",
“app”:“index”,
“method”:“POST”,
“url”:"/index.php/login",
“message”:{
“Exception”:“InvalidArgumentException”,
“Message”:“Username must be string”,
“Code”:0,
“Trace”:[
{
“file”:"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
“line”:166,
“function”:“tryLogin”,
“class”:“OC\Core\Controller\LoginController”,
“type”:"->",
“args”:[
“*** sensitive parameters replaced ***”
]
},
{
“file”:"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
“line”:99,
“function”:“executeController”,
“class”:“OC\AppFramework\Http\Dispatcher”,
“type”:"->",
“args”:[
{
class”:“OC\Core\Controller\LoginController”
},
“tryLogin”
]
},
{
“file”:"/var/www/nextcloud/lib/private/AppFramework/App.php",
“line”:126,
“function”:“dispatch”,
“class”:“OC\AppFramework\Http\Dispatcher”,
“type”:"->",
“args”:[
{
class”:“OC\Core\Controller\LoginController”
},
“tryLogin”
]
},
{
“file”:"/var/www/nextcloud/lib/private/AppFramework/Routing/RouteActionHandler.php",
“line”:47,
“function”:“main”,
“class”:“OC\AppFramework\App”,
“type”:"::",
“args”:[
“OC\Core\Controller\LoginController”,
“tryLogin”,
{
class”:“OC\AppFramework\DependencyInjection\DIContainer”
},
{
“_route”:“core.login.tryLogin”
}
]
},
{
“function”:"__invoke",
“class”:“OC\AppFramework\Routing\RouteActionHandler”,
“type”:"->",
“args”:[
{
“_route”:“core.login.tryLogin”
}
]
},
{
“file”:"/var/www/nextcloud/lib/private/Route/Router.php",
“line”:297,
“function”:“call_user_func”,
“args”:[
{
class”:“OC\AppFramework\Routing\RouteActionHandler”
},
{
“_route”:“core.login.tryLogin”
}
]
},
{
“file”:"/var/www/nextcloud/lib/base.php",
“line”:975,
“function”:“match”,
“class”:“OC\Route\Router”,
“type”:"->",
“args”:[
“/login”
]
},
{
“file”:"/var/www/nextcloud/index.php",
“line”:42,
“function”:“handleRequest”,
“class”:“OC”,
“type”:"::",
“args”:[

        ]
     }
  ],
  "File":"\/var\/www\/nextcloud\/core\/Controller\/LoginController.php",
  "Line":285,
  "CustomMessage":"--"

},
“userAgent”:“Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36”,
“version”:“16.0.1.1”
}

##############################################################################

{
“reqId”:“yt2mnfK7WCijKP1v4sRa”,
“level”:3,
“time”:“2019-06-11T20:56:40+00:00”,
“remoteAddr”:"<my_ip>",
“user”:"–",
“app”:“PHP”,
“method”:“POST”,
“url”:"/index.php/login",
“message”:“Unknown: POST Content-Length of 194 bytes exceeds the limit of 32 bytes at Unknown#0”,
“userAgent”:“Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36”,
“version”:“16.0.1.1”
}

I have the same problem some one help

Same problem:
Update from 15.0.14 to 16.0.0 with updater or manual -> error “Username must be string”

Nextcloud version : 16.0.0 (also tried 16.0.9)
Operating system and version : Ubuntu 18.04
Apache or nginx version : Apache 2.4.29
PHP version : 7.3.16

php -v
PHP 7.3.16-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: Mar 20 2020 13:51:46) ( NTS )


phpinfo.php:
Configuration File (php.ini) Path /etc/php/7.3/apache2


php -m
[PHP Modules]
apcu
bz2
calendar
Core
ctype
curl
date
dom
exif
fileinfo
filter
ftp
gd
gettext
hash
iconv
igbinary
imagick
imap
intl
json
libxml
mbstring
memcache
mysqli
mysqlnd
openssl
pcntl
pcre
PDO
pdo_mysql
Phar
posix
pspell
readline
recode
redis
Reflection
session
shmop
SimpleXML
sockets
sodium
SPL
standard
sysvmsg
sysvsem
sysvshm
tidy
tokenizer
wddx
xml
xmlreader
xmlrpc
xmlwriter
xsl
Zend OPcache
zip
zlib

[Zend Modules]
Zend OPcache

sudo apache2ctl -M
Loaded Modules:
core_module (static)
so_module (static)
watchdog_module (static)
http_module (static)
log_config_module (static)
logio_module (static)
version_module (static)
unixd_module (static)
access_compat_module (shared)
alias_module (shared)
auth_basic_module (shared)
authn_core_module (shared)
authn_file_module (shared)
authz_core_module (shared)
authz_host_module (shared)
authz_user_module (shared)
autoindex_module (shared)
deflate_module (shared)
dir_module (shared)
env_module (shared)
filter_module (shared)
headers_module (shared)
mime_module (shared)
mpm_prefork_module (shared)
negotiation_module (shared)
php7_module (shared)
proxy_module (shared)
proxy_html_module (shared)
proxy_http_module (shared)
reqtimeout_module (shared)
rewrite_module (shared)
setenvif_module (shared)
socache_shmcb_module (shared)
ssl_module (shared)
status_module (shared)
xml2enc_module (shared)

I switched back to 15.0.14 which runs without problems.