Error SAML Auth FortiOS 7.4.1

[Pedroso]

Hi Guys, I have a problem after update my FGT 200E to 7.4.1, my SAML auth was operating normally, now I can't loggin to administrate firewall, I already did a new configuration on FGT and Azure but I receive the same error.

"AADSTS7500525: There was an XML error in the SAML message at line 1, position 503. Verify that the XML content of the SAML messages conforms to the SAML protocol specifications."

Someone also had this error and know how to fix it ?

Tks

[dbu]

Hi @Pedroso ,
It looks like the entity id is set to empty for the SP in the Fortigate. 
Configure it manually from the CLI as it was before the upgrade. Check the backup file.

#config system saml
#set entity-id <SP entity ID>

#end

[Pedroso]

I was comparing the actual config version (7.4.1) with the bkp version (7.2.5), I noticed that the version had a "set artifact-resolution-url "https://x.x.x.x:xx/saml/?artifact", and new version there isn't this.

I already tried every thing.

Sad :\ 

[Pedroso · Accepted solution]

I found the solution, @dbu your tip was helpful, but I show the path that I can resolve the problem:

Go to Settings, Fabric SSO

Click on "Security Fabric settings" and next "Advance Options"

Expand SP Details, you will notice that "SP entity ID" is blank

Insert your http ID, for example: http://fwtest.com:1111/metadata/

Now your SAML auth is working again.