For some reason I cannot install plugin from marketplace using web-interface, there is no 'Install' tab:
Is there something wrong with permissions? Maybe OS of the instance matters (it is a Windows installation)? For example, I do not have this problem with another instance of JIRA installed on Red Hat.
Only a JIRA System Administrator can install a plugin on JIRA. There are a few actions which a JIRA System Administrator can perfrom, but JIRA Administrator cannot perform.
Take a look at this link for details
Since you say that it is a Windows Installation, I am assuming that you are using the JIRA Standalone instance and not OnDemand. Make sure that the user trying to install the plugin has System Administration Permission.
For a JIRA OnDemand instance, you will have to call up Support and ask them to install the plugin on your instance.
Kiran H S
Hey Community mates! Claire here from the Software Product Marketing team. We all know software development changes rapidly, and it's often tough to keep up. But from our research, we've found the h...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs