When attempting to share a database or create a remote database, you find that respective option is grayed out.
There is more than one possible cause for this issue:
User Account Control / Windows® Account Permissions
This can be caused by the User Account Control (UAC) security of Microsoft® Windows® by limiting application software to standard user privileges until an administrator authorizes an increase in privilege level.
You can work around this issue by launching ACT! as an administrator
Answer ID: How To Enable the Built-In Administrator Account in Windows 10
Damaged Act! Preferences
This issue can result from a damaged Act! preferences file. You can attempt to resolve by manually rebuilding the preferences file. For instructions, please see the section called Alternate Method: Manually Rebuilding Preferences in the bottom half of the following Knowledgebase article:
Answer ID: How to rebuild the Act! Preferences file
Additional Options for Create Remote Database:
Synchronization not Enabled
In order to create a remote database, you must first enable synchronization in your main database. To this click the Enable Synchronization option in the Synchronization Panel.
No Sync Sets Created
In order to create a new remote database, you must first create a least one sync set to use with the remote. To create a new sync set, click the Manage Sync Set option on the Synchronization Panel, then click Create New Sync Set. For detailed instructions on how to manage sync sets, please see the following Knowledgebase article:
Answer ID: How to Manage Remote Database Sync Sets in Act!