i am using the odbc data sources ( created from the control panel --> administrative tools --> odbc data sources ) to connect the crystal report to my access database . all things good and the data sources works like a charm , till i discover that generating the report several times quickly can corrupt the odbc data sources and give an error , noting that the crystal report contains dynamic values for filtering ( a prompt window appear for the values parameters when generating the report ) , check the print screen attached that shows u the error , the database is access 2010 and the report placed in a windows server 2008 R2 XEON 16 GB . a89d0e77f22cf59e358dc1dc0117e645

You could fill a dataset in code and pass it to crystal if you wanted to skip using a odbc.

See this article for programmaticly setting the datasource for crystal.

See this article for filling a DataSet.

how i can make my odbc connection more faster when generating data throug it

If you are dealing with large amounts of data, you will have a hard time "optimizing" this. You may also want to try a DataReader. They will only grab the data, but not store it in local memory.

ok but i am using the dynamic values parameters in crytsal report for filtering , in the pop up windows the error is appearing, check the print screen above ,

The username/password window is popping up when you use a datareader?

yes after several successive generates of the report through vb ..

This is begginning to sound a lot like a crystal problem and not a vb.net problem.

Have you contacted their support team?

Beware! Ask about a price (if any) or you may be hit with a "small" phenomenal fee.

yeh its a crystal report problem , but why the report generate normally up to 8 times and syddenly give this error its seems that the odbc data sources that are linked to the database can't handle a lot of data load

It could be a limitation in their software.

Possibly a datasource not being release or plain ole memory leak.

Anything is possible when using 3rd party software.