Error with NullableArrays when trying to install or remove packages or run Pkg.update()

When I try to add or remove any packages or even run Pkg.update() with Julia, I get the following error:

ERROR: resolve is unable to satisfy package requirements.
 The problem was detected when trying to find a feasible version
 for package NullableArrays.
 However, this only means that package NullableArrays is involved in an
 unsatisfiable or difficult dependency relation, and the root of
 the problem may be elsewhere.

What does this error message even mean and how can I fix this? Thanks for any help in advance.

Is this JuliaPro? If so, this looks similar to Pkg problems - Impossible to update packages and to install some of them and NullableArrays: resolve is unable to satisfy package requirements

Can you try the regular command line Julia from ?

@rdeits Yes I indeed am using JuliaPro at the moment. Guess I’ll have to go back again to plain Julia then.

As much as I respect the effort of the JuliaPro team, I am wondering if the product is beneficial at the current stage of the package ecosystem. Specifically, things move fast, and it is the users who think they are using a user-friendly solution who are hit by these issues.

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Yeah, we had to specifically discourage JuliaPro usage during the robotics tutorial we ran last week because of this issue. I’m hoping the situation will improve with Pkg3 (second only to Cassette.jl on my list of future-packages-that-will-solve-all-my-problems).

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You can follow these steps to fix the package resolve issues in JuliaPro v0.6.2.2

  • Open your JuliaPro command prompt and find the path of REQUIRE file by executing following command:
  • Take a backup of REQUIRE file

  • Open the REQUIRE file in a text editor of your choice and replace following line

Compat 0.55.1 0.55.1+



  • Once you’ve saved above changes, execute following command in JuliaPro command prompt:


Just a heads up: - If you had installed JuliaPro with admin privileges, then you have to launch JuliaPro REPL (JuliaPro command prompt) as admin to perform last step.


Thanks a million for this solution to the problem I also shared.
Unfortunately, for me, the solution is only a magic incantation. Let’s hope the inscrutable problems will subside!

I tried this solution, but it didn’t work… When I open the REQUIRE file in a text editor, I only have 2 lines of text. Compat 0.55.1 0.55.1+ appears somewhere in the first line, but when I replace it by Compat and run Pkg.resolve(), there is an error: Julia is not able to read the two lines because all commands are written sequentially and changing Compat induces an error of reading