shipstation plugin causes order details page to go blank

-- HikaShop version -- : 3.1.1
-- Joomla version -- : 2.5.28
-- PHP version -- : 5.6
-- Browser(s) name and version -- : firefox
-- Error-message(debug-mod must be tuned on) -- : white screen

customer installed shipstation integration plugin on test site on subfoler off root. /test18

plugin worked great.

installed plugin on live site on root.

plugin installed fine but when go to check an order detail page, the screen goes white?

this is the error message when accessing an order details page:

Fatal error: Class 'hikaInput' not found in /home/hy0mbt0wogpa/public_html/e-force.com/test18/plugins/system/shipstation/shipstation.php on line 639

this is on the test folder /test18 live site does the same white page

The shipstation plugin successfully sends orders from Hikashop into the Shipstation platform. the issue is the white blank page when accessing a single order detail when the plugin is enabled. Access to individual orders works fine if the plugin is turned off.

Any help you can provide would be greatly appreciated.

This is a client I had a couple years back and we purchased your Hikashop Business, they asked for a lot of crazy variations, modifications and your system always came through, thanks!

**FYI** They do not want to upgrade anything, so any help along the lines of not upgrading their php level or joomla level, etc would be greatly appreciated. I am doing these guys a favor by contacting you since i dont work for them, so any help to resolve this issue would be apprecitated. I am NOT a programmer, I am a designer with a decent knowledge of Joomla and your Hikashop but altering php files is something I am not comfortable with at almost any level.

I look forward to any help you can provide.

Plugin installation successful. Once again, thank you for your help and wonderful component. I have been asked to look into other ecommerce sites such as shopify, prestashop and woocommerce and they all were lacking in comparison to what your platform offers and in levels of functionality. Great work.

Hi Nicholas,
I did leave a nice review for you.

This just came in so I'm not sure if its the pluging code or Shipstation themselves. Local state tax is used for products shipped in state.

It seems tax is being added to a product then exported to Shipstation as the product cost then tax is exported again in effect causing double taxation for each order. The attached Shipstation page was for an order that was $74.50 and you can see how the price is exported as $79.90 and then tax is added again The other attachments are code grabs from the guys at Shipstation pointing out where they think the issue is.