Hi Soph,
based on the error message I guess you are talking about Campaign Classic (xtk:folder is not used in ACS)
The objects you are trying to import are having some dependency which is not included in the package:
10:01:31 - An element with schema 'xtk:folder' and key(s) '/@name' of value 'qFolder138' is missing in the instance but is a prerequisite for the package.
Ways to solve this:
* create a folder with name qFolder138 on the instance
* include the folder in the package definition (though then recommendation would be to give it a more useful name like qFolderImportWorkflows to prevent potential clashes as qFolder138 is based on an automatic ID which could exist on prod already)