The extension WK4 marks tables (spreadsheets) of the spreadsheet Lotus 1-2-3 from IBM. The extension was used by version 4 of Lotus 1-2-3.
These files contain data in cells organized in columns and rows. In addition, the files may also contain graphics, formulas, and macros. Unfortunately, these macros may also contain malicious code, which is why it is advisable, especially for files from unknown sources, to subject them to virus scanning before executing the macros.
Originally developed by Lotus Corporation, Lotus 1-2-3 was a popular spreadsheet as part of Lotus SmartSuite in the 1990s. IBM acquired Lotus in 1995. The Lotus SmartSuite is discontinued but is still available.
Some versions of Microsoft Excel support Lotus 1-2-3 files, but from version 2007 onwards. The import of files is subject to restrictions, some properties may be lost.
Most often resolving problems with opening WK4 files is very simple. Just install an appropriate program that supports such files. All of the listed programs support WK4 files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of WK4 files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate WK4 files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Lotus 1-2-3 applications is not on the list, select "Browse" option in order to manually locate the directory where Lotus 1-2-3 has been installed.
Sometimes problems with opening WK4 files may not lie with the application itself, but can arise due to other causes, such as: