More than one form was opened at once for the lookup control

After implementing lookup in D365 I encountered an error "More than one form was opened at once for the lookup control" while interacting with control as shown below.

Lookup Code

FormControlEventHandler(formControlStr(SalesTable, LC_AssetGroup_LC_AssetId), FormControlEventType::Lookup)]

public static void LC_AssetGroup_LC_AssetId_OnLookup(FormControl sender, FormControlEventArgs e)

{

    Query                   query = new Query();

    QueryBuildDataSource    queryBuildDataSource;

    SysTableLookup          sysTableLookup;

    sysTableLookup = SysTableLookup::newParameters(tableNum(AssetBook), sender);

    queryBuildDataSource = query.addDataSource(tableNum(AssetBook));

    queryBuildDataSource.addRange(fieldNum(AssetBook, Status)).value(strFmt('((Status == %1) || (Status == %2))', any2int(AssetStatus::Open), any2int(AssetStatus::Closed)));

    sysTableLookup.addLookupField(fieldNum(AssetBook, AssetId), true);

    sysTableLookup.addLookupMethod(tableMethodStr(AssetBook, assetName));

    sysTableLookup.parmQuery(query);

    sysTableLookup.performFormLookup();

}

In order to fix this issue we need to make sure of following things:

• No super() call in lookup code
• FormControlCancelableSuperEventArgs must be used to cancel super()

FormControlCancelableSuperEventArgs event = e as FormControlCancelableSuperEventArgs;

event.CancelSuperCall();

Lookup Code with Fix

[FormControlEventHandler(formControlStr(SalesTable, LC_AssetGroup_LC_AssetId), FormControlEventType::Lookup)]
public static void LC_AssetGroup_LC_AssetId_OnLookup(FormControl sender, FormControlEventArgs e)
{
    Query                   query = new Query();
    QueryBuildDataSource    queryBuildDataSource;
    SysTableLookup          sysTableLookup;

    FormControlCancelableSuperEventArgs event = e as FormControlCancelableSuperEventArgs;

    sysTableLookup = SysTableLookup::newParameters(tableNum(AssetBook), sender);
    queryBuildDataSource = query.addDataSource(tableNum(AssetBook));
    queryBuildDataSource.addRange(fieldNum(AssetBook, Status)).value(strFmt('((Status == %1) || (Status == %2))', any2int(AssetStatus::Open), any2int(AssetStatus::Closed)));
    sysTableLookup.addLookupField(fieldNum(AssetBook, AssetId), true);
    sysTableLookup.addLookupMethod(tableMethodStr(AssetBook, assetName));

    sysTableLookup.parmQuery(query);
    sysTableLookup.performFormLookup();

    event.CancelSuperCall();
}

Hope you find this post useful :)