Why is R2020a slow to return errors?

When I switched to R2020a (Windows), I noticed that a simple error at the command line takes about 20 seconds to resolve,

% Simple mistyping of command "min" cause Matlab to hang for 20 seconds
muin(rand(1,1000));
Unrecognized function or variable 'muin'.

% Nonsense command causes similar hang time
asdfasdfkkasdfasdf
Unrecognized function or variable 'asdfasdfkkasdfasdf'.

Any suggestions of how to eliminate this? I am curious which internal process is hanging.

Answer 1

[Steven Lord]

Do you have any network directories on your MATLAB path? If MATLAB has to search those network directories to determine if there's a potential match to suggest as a correction (the "Did you mean" functionality) that could slow the error process down.

Try temporarily removing those directories from the MATLAB path and check if the problem is resolved.

[KAE]

All path directories are on my local C: drive. However most are under a local OneDrive directory on the C drive. I never had a slowdown prior to R2020a with this path. As suggested, I removed the local OneDrive folder off my path, restarted, and found errors were resolved quickly. Unfortunately I am stuck with having path directories under the local OneDrive folder.

As a workaround, I stopped Matlab from searching for a correction file for a mistyped function by going to the Environment > Preferences tab on the bar at the top of the command line window, as shown below. A mistyped function error is again returned quickly, and it's worth the lack of suggested function names when I mistype them. Note in my 'muin' example above, it wasn't suggesting the correct function name 'min' anyway!

Answer 2

[KAE]

Here is more info on fixing this problem, including the useful function RemoveDrivesFromHistory.