MATLAB中plot函数出错

Question

A =[1, 2, 3, 1, 3, 5, 6, 2];
plot(A)
Error: File: gobjects.m Line: 1 Column: 1
Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII
characters.

Error in newplot (line 47)
fig = gobjects(0);

Error in matlab.graphics.internal.newplotwrapper (line 12)
axReturn = newplot(varargin{:});

如图所示，MATLAB中plot函数无法正常使用！请问一下这个问题应该怎么解决？

MATLAB版本: 2018 b