Sources of LES Problems
Typical LES Opening Challenges
Mklesson is Not Installed
You encounter an error message such as "%%os%% Can't Open LES Files" when trying to open your LES. If this is the case, it's usually due to the fact that you do not have Mklesson for %%os%% installed on your computer. The typical path of opening your LES with a double-click won't work because %%os%% cannot make the program connection.
Tip: Another LES-related program can be selected to open the file by clicking "Show Apps" and finding the application.
Outdated Mklesson
Sometimes your installed version of Mklesson won't support your Lesson File file. Visit the David A. Wheeler website to download (or purchase) the latest version of Mklesson. The primary cause of this problem is that your Lesson File file was created by a different (newer) version of Mklesson than what's installed.
Tip: Right-clicking on your LES, then clicking "Properties" (Windows) or "Get Info" (Mac), can provide clues about your file version.
Regardless, most of the LES file opening problems relate to not having the right version of Mklesson installed.
Other LES File Opening Causes
Even with the correct version of Mklesson installed, you can still experience difficulties opening LESs. If you are still having problems opening LES files, there may be other issues that are preventing you from opening these files. Problems unrelated to software:
- LES file references in the Windows Registry are broken
- Deletion of the LES file description from the Registry by mistake
- Partial installation of Mklesson that did not fully complete
- The LES itself is corrupted
- Malware-tainted LES file can't be opened
- LES-related hardware has device drivers that obsolete
- Too many applications are open on your PC to load your Lesson File file successfully
Quiz: Which image file type is the most popular format used on websites?
That's Correct!
PNGs are just slightly more popular than JPEG files (74.5% vs. 72.8% of websites using them) according to usage data from W3Techs.com.
Close, but not quite...
PNGs are just slightly more popular than JPEG files (74.5% vs. 72.8% of websites using them) according to usage data from W3Techs.com.