There are two situations why your graph may not be displaying and each one has a different error message.
1. Error message: "Negative values are invalid for a pie chart"
Your revenue report has an option to display revenue by by service item group. Each group must have a positive value in order for the graph to display. If any single service item group adds up to less than zero (a negative value), the graph will not be displayed and an error message "Negative value are invalid for a pie chart" will be displayed instead.
This help screen provides instructions on how to remedy this.
First, click on the service item group that has the negative value to reveal the service items that make up this group.
In this example the discount service item has a negative value which is causing the service item group to have an overall negative value, so this item needs to be moved to a different service item group.
To change the service item group associated with your service, do the following:
Navigate to ADMIN > SERVICES > SERVICE ITEMS
Choose the service item that is giving the negative result.
Change the service item group (associated with this service) to one that always has positive revenue. Example; Say your walking group always has positive revenue of around $8,000 and your discount item usually has negative values of around -$200. Putting your discount item in the walking group will ensure that the overall revenue of the walking group is still always positive and your graph will then be displayed.
The revenue by service item group pie chart is now showing again.
In this example the admin group is no longer showing a negative value as the discount service item has been moved to another group (the walking group).
2. Error Message: "Cannot read 'Property' length of null" (Chrome) or "null is not an object (evaluating 'c.length')" (Safari) or there may be a blank area with no message
When you run your revenue report you find your graphs won't display in any of the sections. The reason why this occurs is that you are probably viewing your browser page within Chrome at either a zoomed in or out view other than at "actual size" or "100%".
Navigate to the "View Menu" in Chrome.
Click "Actual Size".
Then click "Show Report" again in Pet Sitter Plus. Your graphs should now be displaying.
Once you can see the graphs, you can zoom in or out and they will now display.
This error only seems to happen the first time you use Chrome (or another browser) and once fixed, it doesn't happen again.