This plugin is not valid for older versions of CRM. Prior to 2015 OnLine, I guess.
For example, when I'm connecting to CRM 2013 I'm getting following exception, that actually makes sense for me as a developer, but looks too techy for normal user:
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Load
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Failed to load date constraints:
The entity with a name = 'plugintracelog' was not found in the MetadataCache.
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OK
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It's possible to dismiss that message and see plugin. Which will be completely unusable.
I think it would be better to inform user right away, that organization he tries to connect is not supported, since required entities are missing.