Answer

Answer
Fixed
This is fixed for Textastic 3.1.

In the meantime, you can use this workaround:

Add the following line to your Apache config (httpd.conf):

BrowserMatch "^Textastic" redirect-carefully
I could reproduce the issue and found a workaround. It seems to be a problem with how Apache redirects requests for directories that don't end in a slash ("/").

In my Apache config, I found this comment:

# The following directives disable redirects on non-GET requests for
# a directory that does not include the trailing slash.  This fixes a
# problem with several clients that do not appropriately handle
# redirects for folders with DAV methods.
#
BrowserMatch "Microsoft Data Access Internet Publishing Provider" redirect-carefully
BrowserMatch "MS FrontPage" redirect-carefully
BrowserMatch "^WebDrive" redirect-carefully
BrowserMatch "^WebDAVFS/1.[0123]" redirect-carefully
BrowserMatch "^gnome-vfs/1.0" redirect-carefully
BrowserMatch "^XML Spy" redirect-carefully
BrowserMatch "^Dreamweaver-WebDAV-SCM1" redirect-carefully



As soon as I added the following line it worked with Textastic, too:

BrowserMatch "^Textastic" redirect-carefully

If you add this line to your Apache config, Textastic should be able to connect without problems.
Any plans on a client fix?  I have this same error, but I do not own the server, so I cannot change any apache config files.

Thanks.
Yes, this is on my todo list.
Awesome.  Thanks for the reply.
Answer
Fixed
This is fixed for Textastic 3.1.

In the meantime, you can use this workaround:

Add the following line to your Apache config (httpd.conf):

BrowserMatch "^Textastic" redirect-carefully