Please help us help you and fill where relevant:
LimeSurvey version: Upgrade from 2.06 to 6.5.14
Own server or LimeSurvey Cloud: own server
Survey theme/template:
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Hi,

We have upgraded the LimeSurvey from version 2.06 to version 6.5.14. The installation was successful, but we cannot access the existing surveys or create new ones. I am getting the following error messages: 

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 262144 bytes) in /home/hard/web/ieb-web-0005/fbta.ieb.kit.edu/htdocs/limesurvey/application/models/TemplateConfig.php on line 302

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 262144 bytes) in /home/hard/web/ieb-web-0005/fbta.ieb.kit.edu/htdocs/limesurvey/vendor/yiisoft/yii/framework/base/CApplication.php on line 224

I suspect there is a problem with the configuration files, but I do not know where to start. 
Thanks for your support in advance.

Regards

The DB update happen with succes ?
Can you try to activate debug mode ?
How many memory for PHP allowed (6 ask a lot more than 2.6)
 

Hi,

Thank you for your reply. Here my answers:

- The DB was successfully updated.
- Debugging is now active in ...application/config/config.php, so that error messages are displayed.
- The standard 128M (which should be sufficient?).

Thank you in advance.

Regards

Romina Rissetto wrote:

Hi,
- The standard 128M (which should be sufficient?).
 

Try with 512.

With debug : no other error ?