Dear Francois
From the information that you have provided, it sounds like this could be a limitation of Crystal when reporting on very large datasets.
With that in mind, it is not really surprising that after 4 years of accumulating data it seems like 'all of a sudden' the reports are acting strange. In reality, it is more likely a case of the past month or two's data (or even the past few day's data) being the straw that broke the Camel's back.
Now that we have determined that the reports in fact DO work after narrowing down the criteria, my questions/suggestions would be:
1. Is there a possibility that some historical files can be archived or copied somewhere else, then removed to enable QRWIN to do it's job more efficiently again? Does your client really need ALL 4 years of historical data in there for the application being reported on, if they don't actually report on it?
2. Failing this, is it possible to either a) add selection criteria to print only a certain range of data, print the report first with the first range, then a second time using the end range - or - b) copy this report as a new report and modify the selection criteria in both reports so that the 1st report would automatically select the first range - save it then compile it as the 1st report, then do the same for the 2nd report? In this way, the client would not have to remember to enter the selection criteria and print the same report twice, but just run one report after the other.
QRWIN sorts through all records before it prints the data you have selected, so this would be very helpful. You should not have to resort to re-writing the reports from scratch in this case, as we have seen that the reports run just fine if you eliminate some of the criteria.
Hope this gives you some assistance.
Sincerely
Softrak Support