Salesforce - C&P Reports: Argument 1 cannot be null

[skateistan]

Hello there,

I have created a new report and one of the arguments in the filter seems to be null. Unfortunately I can't go back into the report in order to edit this field.
I get the following error:

Argument 1 cannot be null
An unexpected error has occurred. Your solution provider has been notified. (CnP_PaaS)

Since then I have also received one Error Report email about a failed donation with the same system response:
"Insert failed. First exception on row 0; first error: UNABLE_TO_LOCK_ROW, unable to obtain exclusive access to this record: []"

I'm asking for your support in order to resolve this issue asap.

Best,
Manuel

[CnP.Support]

Good day @SKateistan,

The report is no longer being used. The report should be deleted. This report is a legacy report.

If you want we can review your account and remove the legacy reports.