How to upgrade from VM2.0.18a TO VM 3

[losiuhoi]

I had failed to upgrade my VM on a copy of my live site.

If there any Complete Guide for upgrade from VM2.0 to VM3
or any extension make me easier to upgrade my VM

Current Version:
Joomla 2.5.9
VM 2.0.18

Target Version: VM 3

[GJC Web Design]

you just install VM3 over the top of VM2 -- if it fails u need to find out why..

what happened when you say

I had failed to upgrade my VM on a copy of my live site.

You of course need VM3 compatible VM templates .. as a test replace any templates/YOUR_TEMPLATE/html/com_virtuemart/

with the standard ones from the install or just rename that folder so the over rides aren't included

[jenkinhill]

I seem to recall that later VM3 versions will not work on old J2.5 versions, and in any case, J2.5.9 is insecure.  I would suggest updating Joomla to 2.5.27 with the Dec 2015 security patch applied.

Then update VM to the latest version.

Of course this should be tested on a backup/copy of the live site.

[losiuhoi]

I have been upgraded but I got some error message in the website.
May I know what the problem is?

[GJC Web Design]

You need to set up your safe path correctly then see if the not found error is gone

http://docs.virtuemart.net/faqs/110-how-to-set-the-safe-path.html

[losiuhoi]

Safe path problem fixed.

I still got this error message

[GJC Web Design]

No idea-- I don't find that lang constant in VM3.0.16 

[jenkinhill]

COM_VIRTUEMART_FILE_NOT_FOUND is used in mediahandler.php - the ini entry is COM_VIRTUEMART_FILE_NOT_FOUND="File not found %1$s"

But I've never seen it appear

[GJC Web Design]

missing images after your upgrade?

[losiuhoi]

After checking, some images does not existing in live site and my test platform.
But the error message does not display in the live site.

So, how can I disable this error report?

[GJC Web Design]

repair the missing images or try media->
   Synchronize media to VirtueMart