Cannot find Joomla XML installation file and path during installation

I removed the new Joomla 3.7.5 test installation directory and changed the back-end access credentials. Now the vData installation goes through but I just get a source code page in the browser after 1st time authentication.

Can you delete my earlier answer after getting the credentials? I accidentally sent them together with the reply?

I downloaded the package again from WDMtech website. Didn't work for my old Joomla 3.0.3 site. It says JFolder: :files: Path is not a directory. Path: /home/int27824/public_html/tmp/install_59a43303de108

Could it be because my new Joomla 3.7.5 test installation is a subdirectory of the old site? According to Joomla it should work that way as well. I added the new site's database tables to the existing old database. Joomla 3.0.3 site backend can be accessed at discoverit.fi/administrator/index.php?L_08n_k17=A_23e_N01

Credentials:
username: jarkkari
password: P_t13_K_2

Warm regards,
Kai

vData version is 2.9.12

I need to export data from my old Joomla 3.0.3 site to the new 3.7.5 site. When installing the vData package on my 3.0.3 site I get the error saying that 'Cannot find Joomla XML installation file' and further that 'installation path not found' and 'error when installing com_vdata.zip'.

Also when trying to install to the new 3.7.5 site I get the error saying 'unable to write entry' and 'error when installing com_vdata.zip'.