blank screen upon checkout with Paypal standard checkout module

[liz5384]

Hello,

I’m having issues with the Paypal standard checkout module in my oscommerce store - http://www.tygervinum.com/catalog

When I try to make a test payment, I click the confirm order button, but it no longer goes to the Paypal screen. Instead it goes to http://www.tygervinum.com/catalog/index.php(but it shows an empty white screen).

Here's step by step what happens:
- I go to checkout.
- Confirm shipping method
- Select Paypal as my method of payment
- Press the Confirm Order button
- I am redirected to http://www.tygervinum.com/index.php(but the page is blank)
- If I press refresh at this point, I'm taken back to my store's homepage
- I press checkout again
- Confirm shipping method
- Select Paypal as my method of payment
- Press the Confirm Order button
- Then I am taken to the Paypal payment screen

Why do I have to go through this process twice to get to the Paypal payment screen? Why am I not taken there immediately when I press the Confirm Order button the first time?

If you have any suggestions, please explain in simple terms (as I am a novice) what I should try.

[Jack_mcs]

You shouldn't have to go through that. A white screen almost always means a fatal error was encountered. You can check the root directory of your shop (catalog) and see if there is a file named error_log. If there is, it might contain the failure. Also, try enabling either the cod or check/money order payment module and place an order with them. If it fails the same way, then you have something basic wrong with the shop. If it works and you can't find the error, you can ask your host to check the servers error log - some will, some won't. If they won't, post back here and I (someone) can give further troubleshooting tips.

[liz5384]

I enabled my COD and check/money order payment module and placed a test order. It seemed to work fine. Then I tried doing a test payment via my Paypal payment module. I encounterd the same white screen. The only error log I could find was called "CGI Error Logs."  Below is a copy of that log.

20151101T185452: tygervinum.com/catalog/checkout_shipping.php PHP Warning:  mysql_fetch_assoc() expects parameter 1 to be resource, object given in /hermes/waloraweb070/b2899/pow.tygerv/htdocs/catalog/includes/languages/english/modules/shipping/separate.php on line 13  20151101T185454: tygervinum.com/catalog/checkout_shipping.php PHP Warning:  mysql_fetch_assoc() expects parameter 1 to be resource, object given in /hermes/waloraweb070/b2899/pow.tygerv/htdocs/catalog/includes/languages/english/modules/shipping/separate.php on line 13  20151101T185518: tygervinum.com/catalog/checkout_shipping.php PHP Warning:  mysql_fetch_assoc() expects parameter 1 to be resource, object given in /hermes/waloraweb070/b2899/pow.tygerv/htdocs/catalog/includes/languages/english/modules/shipping/separate.php on line 13  20151101T185521: tygervinum.com/catalog/checkout_shipping.php PHP Warning:  mysql_fetch_assoc() expects parameter 1 to be resource, object given in /hermes/waloraweb070/b2899/pow.tygerv/htdocs/catalog/includes/languages/english/modules/shipping/separate.php on line 13  

What does this mean? What should I change?