Hi

everything you need to know about the file attachments is included in this doc:

https://help.k2.com/onlinehelp/k2five/userguide/5.0/default.htm#Create/K2Designer/Controls/FileAttachment/FileAttachmentControl.htm%3FTocPath%3DCreate%7CSmartForms%7CForms%7CControls%7CAttachment%2520Controls%7C_____1

Hope it help.

Regards,

Thabiso Ngobese

K2 will not accept any liability for any issues arising from actions taken in respect of the information provided by any forum member.

Already looked there, it's pretty vague:

"The File Attachment control does not allow uploading of certain types of files, including but not limited to:"

That just says the ones that are definitely excluded, but is there a regular default list of allowed ones?

Good day,

As thabiso metion the document he provided gives details on File attachment reference.

I do not think what files types are allowed is documented  please below screen shot for reference

See below link to blacklist  https://help.k2.com/onlinehelp/k2smartforms/userguide/4.7/default.htm#SF-ViewControls-FileAttachmentWithProgress.html#

Please below extra detail:

 The File Attachment control does not allow uploading of certain types of files, including but not limited to:

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  Extension	Description
  ade	Access Project Extension (Microsoft)
  adp	Access Project (Microsoft)
  app	Executable Application
  asa	ASP declarations file
  ashx	ASP.NET Web handler file. Web handlers are software modules that handle raw HTTP requests received by ASP.NET.
  asmx	ASP.NET Web Services source file
  asp	Active Server Page
  aspx	ASP.net
  bas	BASIC Source Code
  bat	Batch Processing
  cdx	Compound index
  cer	Internet Security Certificate File
  chm	Compiled HTML Help
  class	Java class file
  cmd	DOS CP/M Command File, Command File for Windows NT
  cnt	Help Contents file
  com	Command
  config	Configuration file
  cpl	Windows Control Panel Extension (Microsoft)
  crt	Certificate File
  cs	C# code file
  csh	csh Script
  der	DER Encoded X509 Certificate File
  dll	Windows dynamic-link library
  exe	Executable File
  fxp	FoxPro Compiled Source (Microsoft)
  gadget	Windows Vista gadget
  grp	SmarterMail group file
  hlp	Windows Help File
  hpj	Help project file
  hta	Hypertext Application
  htr	Script file
  htw	HTML document
  ida	Internet Information Services file
  idc	Internet database connector file
  idq	Internet data query file
  inf	Information or Setup File
  ins	IIS Internet Communications Settings (Microsoft)
  isp	IIS Internet Service Provider Settings (Microsoft)
  its	Internet Document Set, Internet Translation
  jar	Java Archive
  javascript	JavaScript Source Code
  jscript	JavaScript Source Code
  js	JavaScript Source Code
  jse	JScript Encoded Script File
  json	JavaScript Object Notation file
  ksh	UNIX Shell Script
  lib	Windows static-link library
  lnk	Windows Shortcut File
  mad	Access Module Shortcut (Microsoft)
  maf	Access (Microsoft)
  mag	Access Diagram Shortcut (Microsoft)
  mam	Access Macro Shortcut (Microsoft)
  maq	Access Query Shortcut (Microsoft)
  mar	Access Report Shortcut (Microsoft)
  mas	Access Stored Procedures (Microsoft)
  mat	Access Table Shortcut (Microsoft)
  mau	Media Attachment Unit
  mav	Access View Shortcut (Microsoft)
  maw	Access Data Access Page (Microsoft)
  mcf	Multimedia Container Format
  mda	Access Add-in (Microsoft), MDA Access 2 Workgroup (Microsoft)
  mdb	Access Application (Microsoft), MDB Access Database (Microsoft)
  mde	Access MDE Database File (Microsoft)
  mdt	Access Add-in Data (Microsoft)
  mdw	Access Workgroup Information (Microsoft)
  mdz	Access Wizard Template (Microsoft)
  msc	Microsoft Management Console Snap-in Control File (Microsoft)
  msh	Microsoft Shell
  msh1	Microsoft Shell
  msh1xml	Microsoft Shell
  msh2	Microsoft Shell
  msh2xml	Microsoft Shell
  mshxml	Microsoft Shell
  msi	Windows Installer File (Microsoft)
  ms-one-stub	Microsoft OneNote stub
  msp	Windows Installer Update
  mst	Windows SDK Setup Transform Script
  ocx	Object Linking and Embedding (OLE) Control Extension
  ops	Office Profile Settings File
  pcd	Visual Test (Microsoft)
  pif	Windows Program Information File (Microsoft)
  pl	Perl script
  plg	Developer Studio Build Log
  prf	Windows System File
  prg	Program File
  printer	Printer file
  ps	Windows PowerShell
  ps1	Windows PowerShell
  ps1xml	Windows PowerShell
  ps2	Windows PowerShell
  ps2xml	Windows PowerShell
  psc1	Windows PowerShell
  psc2	Windows PowerShell
  pst	MS Exchange Address Book File, Outlook Personal Folder File (Microsoft)
  reg	Registration entries
  scf	Windows Explorer command file
  scr	Windows Screen Saver
  sct	Windows Script Component, Foxpro Screen (Microsoft)
  shb	Windows Shortcut into a Document
  shs	Shell Scrap Object File
  shtm	HTML file that contains server-side directives
  shtml	HTML file that contains server-side directives
  soap	Simple Object Access Protocol file
  stm	HTML file that contains server-side directives
  svc	Windows Communication Foundation (WCF) service file
  sys	Real mode device driver
  tmp	Temporary File/Folder
  url	Internet Location
  vb	VBScript File or Any Visual Basic Source
  vbe	VBScript Encoded Script File
  vbs	VBScript Script File, Visual Basic for Applications Script
  vbscript	VBScript Script File, Visual Basic for Applications Script
  vxd	Virtual document exchange
  vscript	VBScript Script File, Visual Basic for Applications Script
  vsix	Visual Studio Extension
  vsmacros	Visual Studio .NET Binary-based Macro Project (Microsoft)
  vsw	Visio Workspace File (Microsoft)
  ws	Windows Script File
  wsc	Windows Script Component
  wsf	Windows Script File
  wsh	Windows Script Host Settings File
  xamlx	Visual Studio Workflow service file
  xnk	Exchange Public Folder Shortcut

  
  

kind regards