Quartus 15.1 has no problem in connecting to a floating license on a remote server. Quartus 18 and 18.1 cannot consistently connect to the remote server, it's nearly impossible to compile a design. What is the difference?

[AR_A_Intel]

Hello

Welcome to INTEL forum. May we know, is there any error when connected to server? Could you provide the error screenshot message?

[FRobe6]

​Hi AAbd

It looks like I have fixed it by downloading and using Quartus 19.1.  Quartus 18.1 still doesn't work consistently, so I am going to use 19.1 from now on. 

Many thanks,

Fergus 

[AR_A_Intel]

Thanks for your update

[FRobe6]

"To work around this problem, adjust the FLEXLM_TIMEOUT environment variable in the client machine, the available range is from 0 to 2,147,483,647 microseconds. Default value is 100 microseconds. 

For example to set the variable to 1 second, set the variable as follows:

FLEXLM_TIMEOUT=100000000"

so I think we should add an environment variable of:

FLEXLM_TIMEOUT=100000000  

[AR_A_Intel]

Yes, This will increase the amount of time for Quartus to wait for a response from the license manager. You can try higher value as well.

https://www.altera.com/support/support-resources/knowledge-base/tools/2016/why-quartus-prime-16-1-failed-to-detect-float-license-.html