Hi,
Once again as it has been said previously by others: your NameMapping uses identification properties that sometimes change their values thus breaking the identification. You must compare initial and newly created mapping, figure-out what was changed, whether the change was caused by developers or by runtime environment and correct your NameMapping to either use new value or to replace unstable identification parameter with the stable one.
As it also has been said, TestComplete tries to make its best guess while doing automatic NameMapping but this might not always work and manual verification and adjustment (if needed) is a good recommended practice.
For example, you may have a web browser mapped using its name (e.g. chrome) and index (e.g. 1). This will work while you have one Chrome browser running but will fail when another instance of Chrome will be started because this will change the value of Index from 1 to 2.
Your case is likewise - some identification property for ScrollViewer has changed. Find what and why was changed and correct the NameMapping to not use unstable properties for identification.
And, in addition to all links to the documentation already mentioned, https://support.smartbear.com/screencasts/testcomplete/reliable-tests-for-dynamic-objects/ webinar might also appear to be useful.