For a particular document library in SP 2013 when i try to upload documents, the dialog box to enter the properties is hidden/trimmed. What can be the issue?
Form fields may be hidden in EditForm.aspx of library. Navigate to EditForm.aspx page and append your item ID
For example https://your site Url/libary name/Forms/EditForm.aspx?ID=Item ID
Edit that page and see if there is any script editor/content editor web part added to hide fields.
Another way is with the help of SharePoint designer. Open a particular library, in that you can see the edit form.aspx and then check any code added to hide.