This is actually a bug which exists in VFP9SP1, but has been fixed in SP2. However, I also see that the documentation is not accurate or complete on this topic. To be able to create an index tag, you need exclusive right to the table. The bug in SP1 is that if you Use a table with no CDX Shared, and then Index on xx Tag yy, you don't get any error, but VFP will change the open status from shared to exclusive without any warning.

So to make it clear, always use a table exclusive when you need to add or delete an index tag.

>Hallo.
>Does anyone has any answer to this.
>
>I have the following code:
>

>Use table1 shared
>Index on field1 tag tfl
>

>This works with VFP9 SP1
>
>BUT... when I try the same code when SP2 has been installed, I get an error for the index line: "File must be opened exclusively."
>
>This code works with SP2:
>

>Use table1 excl
>Index on field1 tag tfl
>

>The only differens in the enviroment is that SP2 has been installed in the second case.
>
>/Kjell