Basic information about 12M file

When there is a problem with opening files with the file extension 12M（*.12M or *.12m）, you do not need a computer expert. In most cases, using the helpful suggestions of experts contained in our website as well as appropriate programs, you can solve the problem with the 12M file yourself.

There are 1 file types using the 12M file extension in our database. In the further part of this page, you will find detail information about all the 12M file with their brief description and a list of programs that support 12M file sorted by operating systems. The table below provides useful information about the 12M file extension. It answers questions such as:
  • What is the 12M file?
  • How to open a 12M file?
  • What programs do I need to open a 12M file?
  • What programs help to create and edit a 12M file?
  • How to convert 12M files to another file format?
  • How to convert another files to 12M file format?


1.Detail information about 12M file extension: Lotus 1-2-3 SmartMaster File

File type Lotus 1-2-3 SmartMaster File Category Spreadsheet Files
Developer IBM File format N/A
Description 12M file is a Lotus 1-2-3 SmartMaster File developed by IBM. A 12M file is a spreadsheet created by Lotus 1-2-3, which is part of IBM Lotus SmartSuite. It contains a pre-designed spreadsheet that allows a user to enter information to create forecasts, financial statements, and budgets. 12M files also include formulas, formatting, and print ranges.
Software programs that will open, edit or convert 12M files

Windows		 IBM Collaboration Solutions



Can't open a 12M file?

When you click a file to open it, operating system examines the filename extension. If operating system recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When operating system does not recognize a filename extension, you receive the following message:

”Can't open this file: example.12M”。

To open this file, you install one of the applications from the list of software programs that you found here, you should be able to open, edit or convert the file with the 12M extension without any issue.


Where I can download the application that support 12M file?

If you do not know where you can download the application from our list, click on the link (which is the name of the program), you will find more information there on the location where to download the required application. Most often they are the websites of software manufacturers.


How to change file associations?

  • Right-click a file with the extension whose association you want to change, and then click "Open With".
  • In the "Open With" dialog box, click the program whith which you want the file to open, or click "Browse" to locate the program that you want.
  • Select the ”Always use the selected program to open this kind of file” check box.


Can I change the extension of 12M files?

Changing the filename extension of a file is not a good idea. When you change a file's extension, you change the way programs on your computer read/open the file. The problem is, changing the file extension does not change the file format. Select a software program from our list and install it on your computer. If the file has not opened correctly, you have to look for a different software program from our list. Sometimes you have to repeat the operation several times.


What else may cause problems width open a 12M file?

The reasons for the lack of the ability to open a 12M file on your computer may be at least several. The easiest thing is to find a suitable application installed on your computer, which will open a 12M file. If there is still something wrong, you might want to check:

  • Whether the 12M file is damaged.
  • Whether the 12M file is incorrectly linked in the registry entries.
  • Whether the 12M file extension has been accidentally removed from the Windows registry.
  • Whether the installation of an application that supports the 12M file format is incompletely.
  • Whether the 12M file is infected.
  • Whether the drivers of the equipment used for opening a 12M file are up to date.
  • Whether your computer has enough hardware resources to open a 12M file.

If the 12M file still not working with your software after eliminating the above shortcomings? That means that the problem is more complex and requires the help of a specialist.