xlsread problem in 2018a

I just try to read an excel file into matlab. I use the very straightforwar call to the function

[NUMERICTrg,TXTTrg,RAWTrg]=xlsread(WrkFl);

and I face an error like the following:

Error: File: xlsread.m Line: 113 Column: 8 Arguments to IMPORT must either end with ".*" or else specify a fully qualified class name: "matlab.io.internal.utility.convertStringsToChars" fails this test.

Error in WrpEvntTtlMaxUpdated (line 32) [NUMERICTrg,TXTTrg,RAWTrg]=xlsread(WrkFl);

What could be the reason?

Best regards,

[Guillaume]

Have you modified xlsread.m by any chance?

Is you path corrupt? Have you tried restoredefaultpath?

[Af]

The WrkFl is jut a file name. I did not modify xlsread, well basically it does not let any editing for that file. After I restarted the computer, it functioned normally. closing down the MATLAB and reopening it was not useful though.