Macro VBA reports "BASIC Runtime Error".What's the problem?

I'm a macro beginner.
I'm currently studying macros, but when I tried to execute the following code,
"BASIC Runtime Error Sub or Function Procedure Undefined"
The error appears and cannot be processed.
What is the problem?

■Environment
　OpenOffice

■Running Macros

SubModule1()

Dima As String
a=Cells(3,2).Value
MsgBox(a)

End Sub

■error statement
　US>BASIC Runtime Error
　Undefined Sub or Function Procedure

■Confirmed
　·Check Tools > Options > Load and Save > VBA Attributes > Executable Code
　·Check Tools > Options > Java > Use Java Runtime Environment
　"·Change the macro placement from ""My Macro"" to ""{File Name}"""
" 　·Save the file as an xlsm file and then run it
　
■Supplement
　Defining a, such as "a="Hello World" will run successfully and
　A message box appears.
　As soon as you use a function that works on a sheet like Range or Cells,
　Now that it doesn't work well, I'm wondering if it's an environmental problem.

These are the issues you are currently experiencing.
If you have experienced a similar problem before, or if you know how to solve it,
Please let me know if you have any questions.

Thank you for your cooperation.