Unable to Update Unifi AP Firmware (Resolved)

Recently i updated my Unifi Controller from v4 to v5.10.26 after which i could not recieve information regarding the units and i was unable to upgrade the APs to the current version.
after numerous checks and online information, i got no where.

 A hint of why it didn't work came from an SSH session while attempting to upgrade.
Assumption here is that your device is properly configured to access the internet.
my AP firmware was v3.7.51.6230.
First step is to upgrade it to v3.7.58.6385, then to current version (v4.0.54)
Attempting to Upgrade direct to v4.0.54 doesn't work and you get and invalid firmware error.

Steps:
1. Proceed to https://www.ui.com/download/unifi/unifi-ap/uaplr .
Note the download link for v3.7.58 of your AP and replace https with http. i.e. https://dl.ui.com/unifi/firmware/U2Sv2/4.0.54.10625/BZ.qca9342.v4.0.54.10625.190801.1544.bin becomes http://dl.ui.com/unifi/firmware/U2Sv2/4.0.54.10625/BZ.qca9342.v4.0.54.10625.190801.1544.bin
2. ssh into the AP
3. type "upgrade http://dl.ui.com/unifi/firmware/BZ2/3.7.58.6385/BZ.ar7240.v3.7.58.6385.170508.0942.bin" (without the quotes). Remember to replace https with http. This only works via ssh console.
4. After upgrade, access the Controller through GUI, you will then notice the AP having the new v3.7.58 firmware.
5. Select AP -->Manage Device --> Custom Upgrade. Enter the download link for the v4.0.54 firmware and remember to replace https with http. click upgrade and wait for it to complete.

when done, you will find the AP upgraded and displaying information as should be.