What is wrong here?

When starting emacs I get a bunch of warnings and when I start it wit --debug-init
it shows me the stuff below. How do I find the location of the problem in my .emacs.d/init.el ?

Debugger entered--Lisp error: (wrong-type-argument sequencep flycheck-yamllint)
  mapc(#<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_7> flycheck-yamllint)
  custom-theme-set-variables(user (add undelete-frame-mode) (column-number-mode t) (custom-safe-themes '("6876d0eb1bcef5ce6a71434d7c19a66a1a14378e22dce3b72b1fbc51aeb5e18d" default)) (dired-listing-switches "-al --group-directories-first") (display-line-numbers-type 'relative) (display-time-mode t) (eudc-default-return-attributes 'all) (eudc-use-raw-directory-names t) (font-use-system-font t) (global-display-line-numbers-mode t) (global-whitespace-mode nil) (k8s-indent-offset 2) (lsp-trim-trailing-whitespace nil) (lsp-warn-no-matched-clients nil) (markdown-command "/usr/bin/pandoc") (nxml-slash-auto-complete-flag t) (org-agenda-files nil) (org-export-with-sub-superscripts '{}) (org-safe-remote-resources '("\\`https://www\\.cybertec-postgresql\\.com\\(?:/\\|\\'\\)")) (minimap lsp-docker lsp-jedi flycheck-yamllint math-preview ansible esup plantuml-mode wgrep dired-subtree k8s-mode vc-msg terraform-mode crontab-mode lsp-ui lsp-mode python-black cl-libify pyenv pyvenv vterm-toggle orgtbl-aggregate auto-complete-nxml html5-schema yasnippet yaml-mode web-mode typing time-ext tile swiper-helm swiper ssh-tunnels ssh-deploy ssh-config-mode ssh-agency ssh speed-type python-mode python powershell org-gnome org nlinum multiple-cursors mic-paren magit load-dir json-mode js2-mode ...) (plantuml-default-exec-mode 'jar t) (plantuml-executable-path "/usr/bin/plantuml" t) (plantuml-jar-path "/usr/share/java/plantuml.jar" t) (reb-re-syntax 'string) (safe-local-variable-values '((conding . utf-8))) (send-mail-function 'mailclient-send-it) (show-trailing-whitespace t) (size-indication-mode t) (sql-electric-stuff 'semicolon) (sql-mysql-login-params '(user password server database port)) (sql-mysql-program "mysql" t) (tool-bar-mode nil) (warning-suppress-types '((comp))))
  custom-set-variables((add undelete-frame-mode) (column-number-mode t) (custom-safe-themes '("6876d0eb1bcef5ce6a71434d7c19a66a1a14378e22dce3b72b1fbc51aeb5e18d" default)) (dired-listing-switches "-al --group-directories-first") (display-line-numbers-type 'relative) (display-time-mode t) (eudc-default-return-attributes 'all) (eudc-use-raw-directory-names t) (font-use-system-font t) (global-display-line-numbers-mode t) (global-whitespace-mode nil) (k8s-indent-offset 2) (lsp-trim-trailing-whitespace nil) (lsp-warn-no-matched-clients nil) (markdown-command "/usr/bin/pandoc") (nxml-slash-auto-complete-flag t) (org-agenda-files nil) (org-export-with-sub-superscripts '{}) (org-safe-remote-resources '("\\`https://www\\.cybertec-postgresql\\.com\\(?:/\\|\\'\\)")) (minimap lsp-docker lsp-jedi flycheck-yamllint math-preview ansible esup plantuml-mode wgrep dired-subtree k8s-mode vc-msg terraform-mode crontab-mode lsp-ui lsp-mode python-black cl-libify pyenv pyvenv vterm-toggle orgtbl-aggregate auto-complete-nxml html5-schema yasnippet yaml-mode web-mode typing time-ext tile swiper-helm swiper ssh-tunnels ssh-deploy ssh-config-mode ssh-agency ssh speed-type python-mode python powershell org-gnome org nlinum multiple-cursors mic-paren magit load-dir json-mode js2-mode ...) (plantuml-default-exec-mode 'jar t) (plantuml-executable-path "/usr/bin/plantuml" t) (plantuml-jar-path "/usr/share/java/plantuml.jar" t) (reb-re-syntax 'string) (safe-local-variable-values '((conding . utf-8))) (send-mail-function 'mailclient-send-it) (show-trailing-whitespace t) (size-indication-mode t) (sql-electric-stuff 'semicolon) (sql-mysql-login-params '(user password server database port)) (sql-mysql-program "mysql" t) (tool-bar-mode nil) (warning-suppress-types '((comp))))
  load-with-code-conversion("/home/erwin/.emacs.d/init.el" "/home/erwin/.emacs.d/init.el" t t)
  load("/home/erwin/.emacs.d/init" noerror nomessage)
  #f(compiled-function () #<bytecode 0x91412cbb2541891>)()
  #f(compiled-function () #<bytecode -0x4307d7bb01d2857>)()
  handler-bind-1(#f(compiled-function () #<bytecode -0x4307d7bb01d2857>) (error) startup--debug)
  startup--load-user-init-file(#f(compiled-function () #<bytecode 0x5b938543da7e629>) #f(compiled-function () #<bytecode 0x731968ef8c7b19b>) t)
  command-line()
  normal-top-level()