MantisHub supports attaching multiple documents to issues (of max size 25MB each). Files can be attached as part of reporting a new issue by clicking on the “Choose File” button and selecting the file via the open file dialog. Files can also be attached later on from the issue view page via the “Upload File” section by choosing the file and clicking “Upload File”. Attachments that are smaller than a configured size threshold (default 256KB) and of type images or text are previewed inline when viewing the issue. Other attachments are only downloaded or opened when clicked by the user.
You can configure the number of attachments that can be added in one batch by going to "Manage - Manage Configuration - Configuration Report" and adding the following option (e.g. 2 attachments):
All Users, All Projects, file_upload_max_num, integer, 2
To increase the max preview size to 1MB (1048576 in bytes), you can add the following configuration option:
All Users, All Projects, preview_attachments_inline_max_size, integer, 1048576