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

[_rb]

you refer to this?

@rprengel

Problem while rendering dashboard element 5 of type combined_graph: Failed to calculate a graph recipe… Have a look at var/log/web.log for further information.

That’s not the same problem.
The main dashboard is the builtin with no changes? Maybe this is related to the autochecks section problems in your update.log