Internal error: invalid literal for int() with base 10: '' when opening main dashboard

I have the same problem after upgrading my personal raw instance from 2.0.0p23 to 2.1.0p1
I fear we could run into this problem at work where the main view is probably customized by dozen’s of colleagues and i don’t want to be the guy to tell all of them that they have to recreate their dashboards.

is there any way on finding out what customization parameter might cause the error? i added some host tag filters to some views and replaced the hexagon statistic fields with a network interface graph.
I’m not a developer but looking at the traceback it looks like some functions for timerange calculation of graphs might be involved.

some info from the error reporting:

Exception

ValueError (invalid literal for int() with base 10: '')

Traceback

  File "/omd/sites/sandsite/lib/python3/cmk/gui/wsgi/applications/checkmk.py", line 241, in _process_request
    resp = page_handler()
  File "/omd/sites/sandsite/lib/python3/cmk/gui/wsgi/applications/utils.py", line 56, in _call_auth
    func()
  File "/omd/sites/sandsite/lib/python3/cmk/gui/pages.py", line 194, in <lambda>
    return (lambda hc: lambda: hc().handle_page())(handle_class)
  File "/omd/sites/sandsite/lib/python3/cmk/gui/pages.py", line 47, in handle_page
    self.page()
  File "/omd/sites/sandsite/lib/python3/cmk/gui/pages.py", line 164, in <lambda>
    "page": lambda self: self._wrapped_callable[0](),
  File "/omd/sites/sandsite/lib/python3/cmk/gui/dashboard.py", line 518, in page_dashboard
    draw_dashboard(name)
  File "/omd/sites/sandsite/lib/python3/cmk/gui/dashboard.py", line 643, in draw_dashboard
    "on_resize_dashlets": _get_resize_dashlets(dashlets),
  File "/omd/sites/sandsite/lib/python3/cmk/gui/dashboard.py", line 711, in _get_resize_dashlets
    on_resize = get_dashlet_on_resize(dashlet)
  File "/omd/sites/sandsite/lib/python3/cmk/gui/dashboard.py", line 1494, in get_dashlet_on_resize
    on_resize = dashlet.on_resize()
  File "/omd/sites/sandsite/lib/python3/cmk/gui/plugins/dashboard/graph.py", line 333, in on_resize
    return self._reload_js()
  File "/omd/sites/sandsite/lib/python3/cmk/gui/plugins/dashboard/graph.py", line 349, in _reload_js
    json.dumps(Timerange.compute_range(self._dashlet_spec["timerange"]).range),
  File "/omd/sites/sandsite/lib/python3/cmk/gui/valuespec.py", line 4617, in compute_range
    count = int(rangespec[:-1])

Local Variables

{'_date_span': <function Timerange.compute_range.<locals>._date_span at 0x7fac2adceee0>,
 '_fixed_dates': <function Timerange.compute_range.<locals>._fixed_dates at 0x7fac2aba5430>,
 '_month_edge_days': <function Timerange.compute_range.<locals>._month_edge_days at 0x7fac2ad84160>,
 'now': 1654103495.080602,
 'rangespec': '0'}