There are a few problems which can arise when running Lertap.
Up until late 2018, the most common problem had to do with macro security. Lertap5, an Excel-based app, is programmed in a language called "VBA", Visual Basic for Applications. Computer code modules written using this language are referred to as "macros".
People who for some reason make it their business to cause havoc with our computers, for example by introducing a virus, have at times done so by nesting nasty, damage-causing computer code, in Excel macros.
To control for this real problem, when a user tries to open an Excel workbook which has macros (such as Lertap5), Microsoft commonly requires users to confirm that it's okay to open the workbook, and Excel may say something like "Hey, the workbook you want to open contains macros, is it really okay to open it?". The way a user indicates her/his approval varies, depending on the version of Excel, but it often involves setting "macro security" levels. Read about doing this by reading this topic.
Microsoft significantly enhanced macro security screening late in the year 2018 with the introduction of an "Anti-malware" screening system. When it comes to Lertap5, this new level of macro security can, and has, caused serious problems; the Lertap5.xlsm workbook has hundreds of macros, and the new security screener can get hung up trying to scan all of them. The result? Excel can appear to hang -- minutes will pass and nothing seems to happen. Or, Excel will just refuse to open the workbook. Or, Excel will agree to open Lertap5.xlsm, but will take minutes to do so (under ordinary conditions, Lertap5.xlsm will open in less than a minute).
There is a solution to this problem. Read about it here.
Minor problems: Excel version compatibility (click here), and an issue that can arise when the Windows Region and Language setting is set to a format where the decimal separator is a comma instead of a full stop. For example, if a test mean is formatted as 50,35 instead of 50.35, some of Lertap's options may fail. The "Res. Charts" option is one; it will produce a "Whoops" error message.
A more complete discussion of issues associated with the various versions of Lertap may be seen at the following URL:
Page forward to take in the macro security, malware-screening, and compatibility mode topics.