TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win v7.0 doesn't support blank space before/after the attribute name and TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win v6.2 support blank spaces.
When migrating from TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win v6.2.x to v7.x if the schema attribute contains blank spaces,
Following error is thrown at TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win publisher end when

TIBCO Enterprise Message Service(TM) is used:

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2018 Feb 26 16:37:37:738 GMT +0530 ABC Error [Subscription] AEADFILES_920002 Subscription error. Subscription service SubscriptionService listening on subject XXXXX. The Repository URL is C:\Tibco_Directories\temp\AT_adfiles_8346572382910971612.dat and the Configuration URL is ABC failed to deserialize the received event. SDK exception thrown is "Attribute not found: XXXXX." 
2018 Feb 26 16:37:37:738 GMT +0530 ABC Error [Subscription] AEADFILES_920003 Subscription error. Subscription service SubscriptionService listening on subject XXXXX. The Repository URL is C:\Tibco_Directories\temp\AT_adfiles_8346572382910971612.dat and the Configuration URL is ABC received inbound event with null data.
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How to remove blank spaces from attribute name in TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win Read/Write Schema.

As a simpler workaround,you don't explicitly have to remove spaces from every attribute,just need to change anything on schema once so that apply button is enabled (dirty mark the schema). In this case, when saved, extra spaces from all attributes will be removed.
At TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win Publisher end you need to perform this step for read schema.In case of TIBCO ActiveMatrix(R) Adapter for Files for Unix/Win Subscriber, you need to perform this at Write schema or directly create a new Write classic schema form read schema after dirty marking the schema.