Can not add attachment to standalone table with error 'Edit operation failed' (ArcGIS Pro)

[Sunnny]

I've created feature layer and standalone table in arcgis portal, then created gdb in arcgis pro.

I've imported feature class and table i gdb, enabled attachments through properties - manage - attachments.

I've also enabled Editor tracking.

I've established relation between feature class and table.

 When I open table, Manage attachment option i enabled and I can choose files I want to attach, but when i click 'open' I get error message 'Edit operation failed.'

[Sunnny · Accepted solution]

OK I've solved this.

I was trying to attach opened file.