Server 500 after click Modifications reflesh button

Hello all,
i have a issue on the reflesh button that case server error 500 on everywhere, error log show:
PHP Parse error: syntax error, unexpected 'elseif' (T_ELSEIF) in /home/dbbeingc/public_html/dummy/system/storage/modification/system/library/cart/cart.php on line 437
i am sure that the cart.php is working fine because i re-upload the same file(same code) can fix server 500 if you dont click the refresh button again...

this happened after i renew and update an extension. for some reason i have to install extension manully.
here is my installation step:
1) express file uplaod to the right directly, for my case i am update my old version extension that would be replace the old file.
2) open install.xml and find the codes which should insert to /system/storage/modification/...
3) go to mySQL `oc_modification` to manully add extension modification recode

after this action, the refresh button on Modifications (admin > extension > Modifications > refresh button)


It there any missing on the installation? Please give me some adivse, thanks

See. viewtopic.php?t=224272

Did anyone can give me some suggestion? thanks

Yes. Disable that vaulty ocmod extension.

Is there any reason why you didn't ask the extension author to fix the extension?