Install failed … parse error

I’m not able to replicate this, have you tried to activate the plugin on another site using a core WordPress theme and disabling all other plugins?

Yep, with theme twentyfifteen and no other plugin activated.
Same error message.
I also tried another WP installation on another server (with other PHP version and so on).
Same error message.
WP version is 4.4.2

I’m grateful you’ve reported this issue but I’m really sorry I still can’t replicate it, is it with the same host? If it is have you reported this issue to them?
Also if you have updated to the latest version 1.1.7 and you still have an error can you notify me of the error you’re logging please.

No, it’s not with the same host. Complete different environment, complete different providers.
Ok. I tried a third environment (a server I run by myself) and it works. So it seems something is here right what’s wrong at the two others. But what is it that’s wrong?
Hm.
The error message remains the same as I wrote above.
Parse error: syntax error, unexpected 'public' (T_PUBLIC) in /var/www/testboks.com/html/tausendsassa/wp-content/plugins/insta-grabagram/admin/class-insta-grab-admin.php on line 309
I updated all three to the latest version 1.1.8.
All others plugins are deactivated and I use a default theme.

What is your environment setup, php version etc, I can see if I can replicate your setup locally and test

PHP Version 5.6.7-1, FastCGI, Memcache … doesn’t work
PHP Version 5.6.4-4ubuntu6.4, Apache 2.0 Handler, Memcache … doesn’t work
PHP Version 5.3.10-1ubuntu3.21, FastCGI … works

Don’t know what else could be important.

Did you ever get to the bottom of this?