You could have some other issue and I couldn't see with certainty
without seeing the issue directly but based on your comments and
your mention of the number of files, I'm inclined to think you are
overloading the array used in the file manager loading the file names
or possibly just exceeding an script time execution limit.
I think your only issue just may be too many filenames to read in the
same folder but not necessarily the files themselves. It would probably
help to move some of your files to a subfolder so that you don't have
so many files located in the same folder location.
That is fine, it still falls to the same recommendation that you
move some of your files to a different folder and try to limit how
many files you have stored in each folder for better organization
and performance of your web hosting account.
When you try to view the list of your files, the file manager program you
are using has to retrieve the full list of files from the operating system
which takes longer if you have a lot of files and then has to load up that
list into an array in memory and process that into some format to display
to you so you can click on whatever file you want to edit. That processing
could take too much time or break if the number of files it has to read
is too much for script memory, array sizes, or set time execution limits
to handle and the way to reduce that is to limit the number of files
that your file manager / web editing program has to handle at once.
Nobody here has advised deleting any files. I do however recommend
you moving some of the files and re-organize how things are stored
in your account a bit to be more efficient instead of lumping all your
files all into the same directory folder which in and of itself isn't a
problem but sounds like you are talking about having a lot of files
and then using web based programs to manage those files and
that can actually be an issue.
It is not necessary to list all that you just typed above but what you
wrote only serves to reinforce what I already suspect and that is
that you have too many files in one place and that is causing issues
for the web based manager program you are using to manage those files.
Again, the problem is not the files themselves or the space they take up!
The problem is the NUMBER of files that are in the same directory which
I think is slowing down the execution of your file manager script enough
that it is failing. Most servers are configured with script memory and
execution time limits and if your web management program is taking too
long to finish processing data when it is loading information such as for
instance the list of files in your account directory, it could terminate
abruptly and not work and possibly give you some kind of "data error".
The issue isn't the size of the files or the space they take up unless
you are talking about actually opening those files in your file manager
but I cannot imagine any web page being that large anyway.
Stop worrying about the space your files are taking. That shouldn't be
an issue unless your host's drives are oversold and full and if that were
the case, you would have a lot more problems to worry about.
We both recommend your changing hosts based on the comments you
made in your original post which seem to indicate that your host either
isn't knowledgeable enough to assist you or doesn't care which means
finding a new host might be beneficial to you.
If you want to stay there then stay there. Regarding your problem
however, outside of getting your host's support to assist you or seeing
the problem myself, my best recommendation to you is to split up your
files into subfolders and update the links in your web pages to link to
the new locations for your files so that you only have a small number
of files in each folder instead of everything all lumped together in one
single place on the server's hard drive all in the same folder.
I think you are explaining things just fine. I am just not so certain
that you are fully understanding what we are saying to you.