ajaxcontroltoolkit older than version 15

[chkuo2]

using vs 2019 community, had some question about build. about ajaxcontroltoolkit older than version 15.
error message "
Severity Code Description Project File Line Suppression State
Error Unknown server tag 'ajaxToolkit:ToolkitScriptManager'. C:\src\sqlwebadmin\SqlWebAdmin\viewTableData.aspx 136
"
Could you give me some suggestion ?

[flight-tom]

I have upgraded the solution to dotnet 4.8, and resolve the problem you are asking.
You can update and try.

[flight-tom]

BTW, after compilation fixed, you may run into a runtime problem about missing a COM component.
Just Google "{10020200-E260-11CF-AE68-00AA004A34D5}" the CLSID, you can find some solutions.