If you are working with Microsoft Dynamics 365 Business Central is trying to personalize some pages, the folllowing may happen:
This is unfortunately a bug for which CU1 will resolve the issue. More information below:
This is a designer bug happening when page customization objects (created and used by the designer) that is performed to ensure their name uniqueness. This is something that we noticed after this was reported to Microsoft CSS and it will be fixed with CU1. Resizing the column width uses the designer in the background even if the user did not enter personalization mode.
Mitigation: In order to mitigate this issue, you need to bring the user back to a situation where all the page customizations that were created for that users have unique names. The only mitigation available now is to remove the user personalization records (see docs.microsoft.com/.../ui-personalization-manage which have colliding names and re-do them if the user wants them back.