Dashboard init failed Template variables could not be initialized

hello Guys,

today I found my docker percona with the following error: “Template variables could not be initialized: Internal Server Error”

It worked fine before. The only thing I can see, is this loop in the /var/log/qan-api.log:

Percona Query Analytics API is running…
2017/09/21 15:25:38 config.go:79: Loading /usr/local/percona/qan-api/src/github.com/percona/qan-api/conf/prod.conf
2017/09/21 15:25:38 config.go:119: API root dir /usr/local/percona/qan-api/src/github.com/percona/qan-api
2017/09/21 15:25:38 base.go:20: Error 1045: Access denied for user ‘qan-api’@‘localhost’ (using password: YES)
Percona Query Analytics API is running…
2017/09/21 15:25:44 config.go:79: Loading /usr/local/percona/qan-api/src/github.com/percona/qan-api/conf/prod.conf
2017/09/21 15:25:44 config.go:119: API root dir /usr/local/percona/qan-api/src/github.com/percona/qan-api
2017/09/21 15:25:44 base.go:20: Error 1045: Access denied for user ‘qan-api’@‘localhost’ (using password: YES)

any ideas ?