The following script, test.fsx does not show any intellisense, tooltips or code lenses:
#load "../foo.fs"
let x = 5
Assume that foo.fs is a file living in the folder directly above the script. It doesn't matter if the code in foo.fs is valid or not.

There are two "workarounds" I have found that fixes the issue:
foo.fs to the same folder level as test.fsx.foo.fs to foo.fsx.However, neither are viable solutions when e.g. working with file dependencies sourced from paket.
I have been having the same issue for the last few versions.
My workaround is to include the project's root folder with an absolute path:
#I "C:/Source/ProjectA"
Then I can reference packages and load .fs-files with intellisense still working:
#r @"packages\FSharp.Data\lib\net45\FSharp.Data.dll"
...
#load @"Reporting\src\MetaData.fs"
...
Maybe something has changed since this was reported, but I'm experiencing this issue with a .fsx loading a .fs in the very same directory, either by using just the filename or a relative path.
Using an absolute path fixes the issue.
@turbohz I'm noticing it now for .fsx files even with absolute paths :-(
Ignore that last message - that was because the referenced .fsx file had a relative #load in it.
Pinging this as it's quite old - just wondering if anything has changed in the ecosystem in this time to fix it - or if not, what steps are required to solve it?
@Krzysztof-Cieslak in new Ionide 4 world, is there any chance that this is "fixable"? :-)

This seems to be working for me

Or not
Fixed in FSAC, will be in next Ionide release.