I have a legacy (v5.x) install of PRTG. I recently rebooted the server after it had been running for a long time (year +). PRTG fails to start as a service. When I try to start the GUI it does the initial startup stuff and then guts stuck at "reading historic data 378/512". I know that there is a folder for each day of monitoring data and there are only 375 folders in the directory. PRTG is set to keep data for only 180 days and I manually remove the monitoring folders after ~ 1 year. So it seems to be looking for data going back 512 days and hangs when it can't find it. How can I set it to only look for data for the last xxx number of days?