Cannot sync with caldav anymore

[<basilio@gmx.com>]

Hi to all!

After updating to Org mode version 9.1.6 (9.1.6-48-gfe7619-elpa) I lost
ability to sync with caldav (which I use for syncing my schedule with
Nextcloud <-> Android). Before the update everything was perfect. And I
beleive that everything is ok with org-caldav as there were no updates
for it this time. I use emacs package system for updating and therefore
I cannot downgrade the org-mode. And I heavily rely on it in my daily
routines. So I'm stuck and need some advice.

Thanks ahead.

PS Org-caldav version is 20170615.724

PPS I'm not proficient at Lisp unfortunately, but the error is following:

Debugger entered--Lisp error: (wrong-type-argument stringp ARCHIVE)
  string-match("{.+?}" ARCHIVE)
  org-tags-expand(ARCHIVE t)
  #[257 "\300\301\"\207" [org-tags-expand t] 4 "\n\n(fn TAG)"](ARCHIVE)
  mapcar(#[257 "\300\301\"\207" [org-tags-expand t] 4 "\n\n(fn TAG)"] (ARCHIVE))
  cl-mapcar(#[257 "\300\301\"\207" [org-tags-expand t] 4 "\n\n(fn TAG)"] (ARCHIVE))
  apply(cl-mapcar #[257 "\300\301\"\207" [org-tags-expand t] 4 "\n\n(fn TAG)"] (ARCHIVE) nil)
  cl-mapcan(#[257 "\300\301\"\207" [org-tags-expand t] 4 "\n\n(fn TAG)"] (ARCHIVE))

  *** some very, very long lines ***

  org-caldav-sync-calendar()
  org-caldav-sync()
  funcall-interactively(org-caldav-sync)
  call-interactively(org-caldav-sync record nil)
  command-execute(org-caldav-sync record)
  execute-extended-command(nil "org-caldav-sync" "org-caldav-sy")
  funcall-interactively(execute-extended-command nil "org-caldav-sync" "org-caldav-sy")
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)