Sometimes it can happen, that you compare two strings, which looks exactly sames, but they are processed as not equal. Also when you use SELECT DISTINCT and still there are rows that looks same, like DISTINCT is not working. Dimensional attribute in OLAP can return errors for duplicities even you used DISTINCT for dimension. This is the right time to search invisible/hidden characters in string. RTrim and LTrim function not stripping whitespace.
In case you need create list off all dimensions used in cube on Microsoft SQL server, with list of all dimension attributes. There is easy and simple way how to do it with query.
If you need calculate week number from date, you can use DATEPART with parameter ISO_WEEK. Unfortunately there is nothing like ISO YEAR parameter. In case you need to show YearWeek value in some report you have to take care about correct value manually.
3 most often reason, when you are using variables in Execute SQL task inside SSIS and get following error:
Error: 0xC002F210 ... , Execute SQL Task: Executing the query "...
..." failed with the following error: "HERE IS IMPORTANT PART". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.