Hi JulieT
I find this is common with many files, one or the other report takes 'ages', depending on the number of customers v. the number of suppliers in the file.
Given this report (Receivables with tax) is an 'as at date' report, Tracey_H suggestion about date range won't help. The timeout extender might.
If this fails you may need to make a backup, restore locally and generate the report that way.
Can I ask why you use this report and not the Receivables Summary Reconciliation? From my experience, this report is more reliable. The Receivables with Tax is known to have errors when finance charges are involved or when multi currency is used.
Regards
Gavin