can I use ML downloader and use Wealthlab 4.0 and Wealthlab 6.0? I did a download in WL over Internet and now I can´t use
my NAS 100 symbol file any more in WL4. I get following message if i click in ML NAS100 + I see the symbols but it says the security symbol does not exist. How do I get the data file back in ML!
IT IS NOT MORE WORKING1

Thant should be no problem. I upgraded to WL6 and still work with WL4 and MLDownloader without any problems.
I would recommend to check your settings within the downloader....

I am working with Metastock Format. At the beginning I set a new datasource with Metastock Format so the same file like in WL4.0 under C:\metastock\USA\NAS100
So I update ML perfect. But if you update additonal with yahoo data suddenly it not working anymore in the downloader.

There's no connection whatsoever between Yahoo! data and data from any other provider. I can't follow your description of the problem though, so it would help to have the exact text of the error. An image of the Wealth-Lab environment wouldn't hurt either.

I delete some datafiles with metastock format in the NAS100 . The problem during the download someone has written additional into this files. Who I don´t know. Same was in TAIPAN as well.
After the download of WL 6.0 I had a new Metastock Export Version. So couldn´t use the data in WL4. Then you have to unstall this again. I am not sure if I download this new Taipan Extension Manager. I am afraid if I am doing this, then I can´t use the data of Taiwan in WL4.
Independance between WL4 and WL6 is true, but sofar for the data it isn´t.

It is working now, Time consuming.

I remember having discussed this before in a ticket with you. Like it or not, it's "DLL Hell" when one legacy app (was it Taipan?) required one (older) version of MetaLib (supporting COM DLL) and the Metastock provider requires a more recent version. DLL Hell is one of the troubles that the .NET framework overcomes.

So not to confuse any other users, for the data there is full independence between WL4 and WL6. WL6 maintains its own data storage. Neither the Yahoo! provider would influence any other vendor's data nor the MetaStock provider is going to affect any data anyhow (it's read-only).