System error 13, Permission denied while running brms model

I recently restart my Azure VM where I have my R-studio setup. The BRMS method brm_multiple was working fine before the restart, but after the restart BRMS start giving following error messages:
“Error in rethrow_call(c_processx_exec, command, c(command, args), pty, :
cannot start processx process ‘./file38cd4e6eee96_threads’ (system error 13, Permission denied) @unix/processx.c:610 (processx_exec)”

Following is the code snippet:

my_prior = c(
prior(normal(0, 1), class = 'b', nlpar = 'x1') + 
prior(beta(a, b), class='b', nlpar='x2', lb=0, ub=1) + 
prior(beta(a, b), class='b', nlpar='x2', lb=0, ub=1)
)

model = brm_multiple(
bf(y ~ x1 + x2 + x3, nl=True) + 
lf(x1 ~ 1) + lf(x2 ~ 0 + x_2) + lf(x3  ~ 0 +x_3),
data = df_split, family = bernoulli("logit"), backend = "cmdstanr", threads = threading(15, grainsize = 625), prior = my_prior, warmup = 1000, chains = 4, cores = 12, seed = 12345, iter = 2000, silent = FALSE, thin = 1)

The above piece of code was running properly before the restart of the machine.

Could you please help on how to solve this issue. I have searched online, but did not get a concrete solution.

Kind Regards

Hello,

This issue is resolved. Reinstalling rstan and brms packages fixed the problem.