4 answers
I personally have not came across the "Variable does not exist: SharePointAPIUtility" error, but it looks like you are trying to accessing non-static data from a static method?Anyway, I personally would recommend using a 3rd party tool from AppExchange to handle the SharePoint integration. As it guarantees forward compatibility with future versions, I think it is a good bet https://www.connecting-software.com/blog/sharepoint-integration-with-salesforce/