Invalid data file from Alpari

Hi!!
I've done backtest with alpari Metatrader and the data from alpari databank for while without problems. Since yesterday I can't make backtest because I get invalid data file error.
The procees I follow is download platform from alpari, install, no open account, delete history files, import data from alpari data bank, open offline chart and run period converter script, after that I open the chart with the data generated from script.
This process has been working but now the chart is opened but when I run strategy tester I get invalid data file error message.
Any help?

Have you looked in the history center to see if you have the downloaded data still there? Are you trying to test recent dates?

Note the following suggestions are contrary to what I normally tell people and may be completely wrong.
If your talking about downloading the history data from the Alpari website I noticed a couple of things. Two days ago the download file ended on January 23 or 24th. The only way I got the information up to the current week was to press the back arrow / Page Up while logged into Alpari until I got 1 min data older than Jan 24th. I then went in the history center and deleted to a clean break like Jan 23rd at midnight. I made sure the end of the imported data matched and then imported. I clicked on every time frame that had bars in it and deleted them using the history center. Then I ran the period separator and the data came out clean for a backtest. I used to stay offline and use offline charts but for some reason it did not work this time. I guessed that the platform somehow noticed it was missing over a month of 1min data so it showed an error. The odd thing was even when I picked dates from a couple of years ago modeling quality was at 88 or 89 until I filled in the last month then it went to 90. I don't know why but it worked fine once I changed the procedure. It could be possible that Strategy tester checks the data from the start of the selected range to the current date rather than on the range selected. I also tried importing the history first and then logging in to get the last month but it deleted the imported history doing it that way.

Any other ideas?

Yes, the data file is in history center and I can view the quotes and open the chart, but I can´t run the strategy tester. I've tried with otrher Metatrader platform downloaded last month and is working fine, if I download a new platform from Alpari the problem appear again.

I think they were doing things on the server today; couldn't connect to the server to look my demo account. Maybe they fluffed up the download file.

I'm still with the problem. Has any of you tried to download a new platform from alpari, download new data file and run strategy tester?

Sorry, not tried... and if you've experienced problems I don't want to mess up a working install. Wait until tomorrow and give them a call. Good luck!