You try to add an attachment to Gmail and you get attachment failed in red letters. The reason seems to be with a setting in Firefox.

To correct this issue, open Firefox and in the address bar type:

about:config

Press enter or return on the keyboard. You’ll then have to agree to void your warranty and be careful.

In the search area type:

network.http.spdy

Double click the Network.http.spdy.enabled so that the value becomes false

Close and restart Firefox

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