Mobile Card builder is blank and shows a white pageIssue When trying to open Mobile Card Builder it displays a blank white page and does not load anythingReleaseAll ReleasesCauseThe Mobile Card Builder uploads its scripts (sys_ux_lib_source_script) as a type attachment, meaning all the code lives in an attached file. https://<instance_name>.service-now.com/nav_to.do?uri=sys_ux_lib_source_script.do?sys_id=4e3203d50730ebdf8da13c3d4ad814ea There could be business rules which are preventing from accessing correctly the attachment table that basically adds an encoded query to sys_attachment queries. This messes with the ability to retrieve MCB's script file, hence the blank page.ResolutionFirstly, Look for Custom Query Business Rules on the sys_attachment table. You have two ways to work around the issue: 1 - Disable the Business rule or add the case to not add the encoded query for sys_ux_lib_source_script attachments. or 2- Change the type of sys_ux_lib_source_script for sn-mobile-studio-itemview-builder to body instead of attachment and the copy the attached file content in the script field We would suggest going with the 1st solution in order to not cause any customization on the OOB sys_ux_lib_source_script record.