For Diskspan archives you only have to set the first archive.

Delete:
ArcFile2=Data.002;DestDir:{app};Type:ARC;Disk:2;
ArcFile3=Data.003;DestDir:{app};Type:ARC;Disk:3;
ArcFile4=Data.004;DestDir:{app};Type:ARC;Disk:4;

For DiskSpan files the correct one is to only inform the first file (.001).
The others below will be extracted automatically.

If using ArcFile1=Data.001 and ArcFile2=Data.002, if it worked the whole game would be extracted in the key ArcFile1= and it would try to start from the middle of the file again until the last part with each new key.

To use manual splitting (Each part on an ArcFile#= key) with UltraArc splited only, but disk space is required on the same {app} drive to join all parts of the ARC before extracting.

thank you I'll try this