I am one of the Sitecore developer of a large Sitecore site, I have been assigned to clean up a project that cleans up a lot of the error logs, These are the errors logs, but since I am new to the project I cant find where these data sources are referenced, also this is a huge site, so clicking each item and checking is not a go.
Logs
NOT A VALID DATASOURCE ERRORS //55 TIMES 6752 11:37:28 WARN '{E99DFA50-A1F7-4534-B728-6D36DA85FEEB}' is not valid datasource. //52 TIMES //THESE 3 ALWAYS AT THE SAME TIME, SHOULD BE ON SAME PAGE 4856 11:38:19 WARN '{8928869D-C464-44B9-BC5D-A9910FDFF69D}' is not valid datasource. 4856 11:38:19 INFO view /Views/Render/check/HTML/Hshotthere.cshtml does not have any version of the data source item 4856 11:38:19 WARN '{57C4C5FF69DE-4D88-ADEC-FACCFF69D383A27B3}' is not valid datasource. //11 TIMES 7144 11:32:29 WARN '{FF69D-21FF69D98-4FEF-BB0E-88A107FF69DA21382}' is not valid