Hi,
I tried to create a report to overview my customers. Filter was only set to "customers", in that all existing were chosen. Set option to "global dashboard". Start-date was set to June 2013 in the past.

Now I get only warnings instead of a report:

Warning: Invalid argument supplied for foreach() in element_children() (line 6428 of D:\xampp\htdocs\erpal\includes\common.inc).
Warning: Illegal string offset '#children' in drupal_render() (line 5893 of D:\xampp\htdocs\erpal\includes\common.inc).
Warning: Illegal string offset '#children' in drupal_render() (line 5903 of D:\xampp\htdocs\erpal\includes\common.inc).
Warning: Illegal string offset '#children' in drupal_render() (line 5941 of D:\xampp\htdocs\erpal\includes\common.inc).
Warning: Illegal string offset '#printed' in drupal_render() (line 5948 of D:\xampp\htdocs\erpal\includes\common.inc).

These lines repeats many times.
I work with xampp win32-1.8.3-4-VC11 (PHP 5.5.11) under Win7 32Bit.

Thanks for any suggestion!