An OTS file contains formatting, formulas, and data that serve as the basis for creating multiple ods (spreadsheets) tables with the same characteristics. Ots files can also contain macros. These macros may contain malicious code, which is why you should do a virus scan before running it.
The template files can be created by the user or come from third-party providers.
The OTS format is part of the Open Document for Office Application Standard, also known as OpenDocument. Originally developed by Sun Microsystems and based on XML, the standard has been defined and developed by the Organization for the Advancement of Structured Information Standards (OASIS).
Most often resolving problems with opening OTS files is very simple. Just install an appropriate program that supports such files. All of the listed programs support OTS files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of OTS 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 OTS 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 OpenOffice.org Calc applications is not on the list, select "Browse" option in order to manually locate the directory where OpenOffice.org Calc has been installed.
Sometimes problems with opening OTS files may not lie with the application itself, but can arise due to other causes, such as: